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Showing new listings for Friday, 22 November 2024
- [1] arXiv:2411.13635 [pdf, html, other]
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Title: WEAVE First Light Observations: Origin and Dynamics of the Shock Front in Stephan's QuintetM. I. Arnaudova, S. Das, D. J. B. Smith, M. J. Hardcastle, N. Hatch, S. C. Trager, R. J. Smith, A. B. Drake, J. C. McGarry, S. Shenoy, J. P. Stott, J. H. Knapen, K. M. Hess, K. J. Duncan, A. Gloudemans, P. N. Best, R. García-Benito, R. Kondapally, M. Balcells, G. S. Couto, D. C. Abrams, D. Aguado, J. A. L. Aguerri, R. Barrena, C. R. Benn, T. Bensby, S. R. Berlanas, D. Bettoni, D. Cano-Infantes, R. Carrera, P. J. Concepción, G. B. Dalton, G. D'Ago, K. Dee, L. Domínguez-Palmero, J. E. Drew, E. L. Escott, C. Fariña, M. Fossati, M. Fumagalli, E. Gafton, F. J. Gribbin, S. Hughes, A. Iovino, S. Jin, I. J. Lewis, M. Longhetti, J. Méndez-Abreu, A. Mercurio, A. Molaeinezhad, E. Molinari, M. Monguió, D. N. A. Murphy, S. Picó, M. M. Pieri, A. W. Ridings, M. Romero-Gómez, E. Schallig, T. W. Shimwell, R. Skvarĉ, R. Stuik, A. Vallenari, J. M. van der Hulst, N. A. Walton, C. C. WorleyComments: 23 pages, 15 figures, accepted for publication in MNRASSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present a detailed study of the large-scale shock front in Stephan's Quintet, a byproduct of past and ongoing interactions. Using integral-field spectroscopy from the new William Herschel Telescope Enhanced Area Velocity Explorer (WEAVE), recent 144 MHz observations from the LOFAR Two-metre Sky Survey (LoTSS), and archival data from the Very Large Array and James Webb Space Telescope (JWST), we obtain new measurements of key shock properties and determine its impact on the system. Harnessing the WEAVE large integral field unit's (LIFU) field of view (90 $\times$ 78 arcsec$^{2}$), spectral resolution ($R\sim2500$) and continuous wavelength coverage across the optical band, we perform robust emission line modeling and dynamically locate the shock within the multi-phase intergalactic medium (IGM) with higher precision than previously possible. The shocking of the cold gas phase is hypersonic, and comparisons with shock models show that it can readily account for the observed emission line ratios. In contrast, we demonstrate that the shock is relatively weak in the hot plasma visible in X-rays (with Mach number of $\mathcal{M} \sim 2 - 4$), making it inefficient at producing the relativistic particles needed to explain the observed synchrotron emission. Instead, we propose that it has led to an adiabatic compression of the medium, which has increased the radio luminosity ten-fold. Comparison of the Balmer line-derived extinction map with the molecular gas and hot dust observed with JWST suggests that pre-existing dust may have survived the collision, allowing the condensation of H$_{2}$ - a key channel for dissipating the shock energy.
- [2] arXiv:2411.13637 [pdf, html, other]
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Title: Do Observations Prefer Thawing Quintessence?Comments: 12 pages, 8 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
In light of recent observations, we study evidence for thawing quintessence over a cosmological constant as dark energy, with emphasis on the effect of the choice of priors. Working with a parametrization for the equation of state parameter motivated by the theory, we find a preference for thawing quintessence compared to a bare cosmological constant {\it only} if we use priors which are heavily informed by the data itself. If we extend the priors to physically better motivated ranges, the evidence for thawing quintessence disappears.
- [3] arXiv:2411.13640 [pdf, html, other]
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Title: A Glimpse at the New Redshift Frontier Through Abell S1063Vasily Kokorev, Hakim Atek, John Chisholm, Ryan Endsley, Iryna Chemerynska, Julian B. Muñoz, Lukas J. Furtak, Richard Pan, Danielle Berg, Seiji Fujimoto, Pascal A. Oesch, Andrea Weibel, Angela Adamo, Jeremy Blaizot, Rychard Bouwens, Miroslava Dessauges-Zavadsky, Gourav Khullar, Damien Korber, Ilias Goovaerts, Michelle Jecmen, Ivo Labbé, Floriane Leclercq, Rui Marques-Chaves, Charlotte Mason, Kristen B. W. McQuinn, Rohan Naidu, Priyamvada Natarajan, Erica Nelson, Joki Rosdahl, Alberto Saldana-Lopez, Daniel Schaerer, Maxime Trebitsch, Marta Volonteri, Adi ZitrinComments: 15 pages, 7 figures, 1 table. Submitted to ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
We report the discovery of five galaxy candidates at redshifts between $15.9<z<18.6$ in JWST observations from the GLIMPSE survey. These robust sources were identified using a combination of Lyman-break selection and photometric redshift estimates. The ultra-deep NIRCam imaging from GLIMPSE, combined with the strong gravitational lensing of the Abell S1063 galaxy cluster, allows us to probe an intrinsically fainter population (down to $M_{\rm UV}=-17.5$ mag) than previously achievable. These galaxies have absolute magnitudes ranging from $M_{\rm UV}= -17.7$ to $-18.0$ mag, with UV continuum slopes between $\beta \simeq -2.3$ and $\beta \simeq -3.0$, consistent with young, dust-free stellar populations. The number density of these objects, log$_{\rm 10}$ ($\phi$/[Mpc$^{-3}$ mag$^{-1}$])=$-3.43^{+0.28}_{-0.64}$ at $M_{\rm UV}=-18$ is in clear tension with pre-JWST theoretical predictions, extending the over-abundance of galaxies from $z\sim10$ to $z\sim 18.6$. These results, together with the scarcity of brighter galaxies in other public surveys, suggest a steep decline in the bright-end of the UV luminosity function at $z \sim 17$, implying efficient star formation and possibly a close connection to the halo mass function at these redshifts. Testing a variety of star formation histories suggests that these sources are plausible progenitors of the unusually UV-bright galaxies that JWST now routinely uncovers at $z = 10-14$. Overall, our results indicate that the luminosity distribution of the earliest star-forming galaxies could be shifting towards fainter luminosities, implying that future surveys of cosmic dawn will need to explore this faint luminosity regime.
- [4] arXiv:2411.13648 [pdf, html, other]
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Title: Accurate Shear Estimation with Fourth-Order MomentsComments: 13 pages, 10 figures. For submission to MNRASSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
As imaging surveys progress in exploring the large-scale structure of the Universe through the use of weak gravitational lensing, achieving subpercent accuracy in estimating shape distortions caused by lensing, or shear, is imperative for precision cosmology. In this paper, we extend the \texttt{FPFS} shear estimator using fourth-order shapelet moments and combine it with the original second-order shear estimator to reduce galaxy shape noise. We calibrate this novel shear estimator analytically to a subpercent level accuracy using the \texttt{AnaCal} framework. This higher-order shear estimator is tested with realistic image simulations, and after analytical correction for the detection/selection bias and noise bias, the multiplicative shear bias $|m|$ is below $3\times10^{-3}$ ($99.7\%$ confidence interval) for both isolated and blended galaxies. Once combined with the second-order \texttt{FPFS} shear estimator, the shape noise is reduced by $\sim35\%$ for isolated galaxies in simulations with HSC and LSST observational conditions. However, for blended galaxies, the effective number density does not significantly improve with the combination of the two estimators. Based on these results, we recommend exploration of how this framework can further reduce the systematic uncertainties in shear due to PSF leakage and modelling error, and potentially provide improved precision in shear inference in high-resolution space-based images.
- [5] arXiv:2411.13655 [pdf, html, other]
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Title: CHANCES, The Chilean Cluster Galaxy Evolution Survey: selection and initial characterization of clusters and superclustersCristóbal Sifón, Alexis Finoguenov, Christopher P. Haines, Yara Jaffé, B. M. Amrutha, Ricardo Demarco, E. V. R. Lima, Ciria Lima-Dias, Hugo Méndez-Hernández, Paola Merluzzi, Antonela Monachesi, Gabriel S. M. Teixeira, Nicolas Tejos, Pablo Araya-Araya, Maria Argudo-Fernández, Raúl Baier-Soto, Lawrence E. Bilton, C. R. Bom, Juan Pablo Calderón, Letizia P. Cassarà, Johan Comparat, H. M. Courtois, Giuseppe D'Ago, Alexandra Dupuy, Alexander Fritz, Rodrigo F. Haack, Fabio R. Herpich, E. Ibar, Ulrike Kuchner, Amanda R. Lopes, Sebastian Lopez, Elismar Lösch, Sean McGee, C. Mendes de Oliveira, Lorenzo Morelli, Alessia Moretti, Diego Pallero, Franco Piraino-Cerda, Emanuela Pompei, U. Rescigno, Rory Smith, Analía V. Smith Castelli, Laerte Sodré Jr, Elmo TempelComments: 11 pages, 9 figures, plus references and appendix containing catalog tables, submitted to A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
CHANCES, the CHileAN Cluster galaxy Evolution Survey, will study the evolution of galaxies in and around ${\sim}$150 massive galaxy clusters, from the local universe out to z=0.45. CHANCES will use the new 4MOST Spectroscopic Survey Facility on the VISTA 4m telescope to obtain spectra for ${\sim}$500,000 galaxies with magnitudes $r_\mathrm{AB} < 20.5$, providing comprehensive spectroscopic coverage of each cluster out to $5r_{200}$. Its wide and deep scope will trace massive and dwarf galaxies from the surrounding filaments and groups to the cores of galaxy clusters, enabling the study of galaxy pre-processing and the role of the evolving environment on galaxy evolution. In this paper we present and characterize the sample of clusters and superclusters to be targeted by CHANCES. We used literature catalogues based on X-ray emission and Sunyaev-Zel'dovich effect to define the cluster sample in a homogeneous way, with attention to cluster mass and redshift, as well as the availability of ancillary data. We calibrated literature mass estimates from various surveys against each other and provide an initial mass estimate for each cluster, which we used to define the radial extent of the 4MOST coverage. We also present an initial assessment of the structure surrounding these clusters based on the redMaPPer red-sequence algorithm as a preview of some of the science CHANCES will enable.
- [6] arXiv:2411.13657 [pdf, html, other]
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Title: A Unified Model of Kilonovae and GRBs in Binary Mergers Establishes Neutron Stars as the Central Engines of Short GRBsSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We expand the theoretical framework by Gottlieb el al. (2023), which connects binary merger populations with long and short binary gamma-ray bursts (lbGRBs and sbGRBs), incorporating kilonovae as a key diagnostic tool. We show that lbGRBs, powered by massive accretion disks around black holes (BHs), should be accompanied by bright, red kilonovae. In contrast, sbGRBs - if also powered by BHs - would produce fainter, red kilonovae, potentially biasing against their detection. However, magnetized hypermassive neutron star (HMNS) remnants that precede BH formation can produce jets with power ($P_{\rm NS} \approx 10^{51}\,{\rm erg\,s^{-1}}$) and Lorentz factor ($\Gamma>10$), likely compatible with sbGRB observations, and would result in distinctly bluer kilonovae, offering a pathway to identifying the sbGRB central engine. Recent modeling by Rastinejad et al. (2024) found luminous red kilonovae consistently accompany lbGRBs, supporting lbGRB originating from BH-massive disk systems, likely following a short-lived HMNS phase. The preferential association of sbGRBs with comparably luminous kilonovae argues against the BH engine hypothesis for sbGRBs, while the bluer hue of these KNe provides additional support for an HMNS-driven mechanism. Within this framework, BH-NS mergers likely contribute exclusively to the lbGRB population with red kilonovae. Our findings suggest that GW170817 may, in fact, have been an lbGRB to on-axis observers. Finally, we discuss major challenges faced by alternative lbGRB progenitor models, such as white dwarf-NS or white dwarf-BH mergers and accretion-induced collapse forming magnetars, which fail to align with observed GRB timescales, energies, and kilonova properties.
- [7] arXiv:2411.13659 [pdf, html, other]
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Title: Pulsating ultraluminous X-ray sources: modeling the thermal emission and polarization propertiesComments: 17 pages, 11 figures, Accepted for publication in A&ASubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Ultraluminous X-ray sources (ULXs) are enigmatic sources first discovered in the 1980s in external galaxies. They are characterized by their extraordinarily high X-ray luminosity, which often exceeds $10^{40}\, \rm{erg \; s^{-1}}$. Our study aims to obtain more information about pulsating ULXs (PULXs), first of all, their viewing geometry, since it affects almost all the observables, such as the flux, the pulsed fraction, the polarization degree (PD), and polarization angle (PA). We present a simplified model, which primarily describes the thermal emission from an accreting, highly magnetized neutron star, simulating the contributions of an accretion disk and an accretion envelope surrounding the star magnetosphere, both described by a multicolor blackbody. Numerical calculations are used to determine the flux, PD, and PA of the emitted radiation, considering various viewing geometries. The model predictions are then compared to the observed spectra of two PULXs, M51 ULX-7 and NGC 7793 P13. We identified the best fitting geometries for these sources, obtaining values of the pulsed fraction and the temperature at the inner radius of the disk compatible with those obtained from previous works. We also found that measuring the polarization observables can give considerable additional information on the source.
- [8] arXiv:2411.13660 [pdf, html, other]
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Title: Radial Metallicity Gradients for the Chemically Selected Galactic Thin Disc Main-Sequence StarsComments: 19 pages, including 15 figures & 1 table, accepted for publication in Astronomische Nachrichten. We would like to especially thank the editorial board for their contribution to the publication of the studySubjects: Astrophysics of Galaxies (astro-ph.GA)
{We present the radial metallicity gradients within the Galactic thin disc population through main-sequence stars selected on the chemical plane using GALAH DR3 accompanied with Gaia DR3 astrometric data. The [Fe/H], [$\alpha$/Fe] and [Mg/H] radial gradients are estimated for guiding radius as $-0.074\pm 0.006$, $+0.004\pm0.002$, $-0.074\pm0.006$ dex kpc$^{-1}$ and for the traceback early orbital radius as $-0.040\pm0.002$, $+0.003\pm 0.001$, $-0.039\pm 0.002$ dex kpc$^{-1}$ for 66,545 thin-disc stars, respectively. Alteration of the chemical structure within the Galactic disc caused by the radial orbital variations complicates results for the radial metallicity gradient. The effect of radial orbital variations on the metallicity gradients as a function on time indicates the following results: (i) The presence of a gradient along the disc throughout the time for which the model provides similar prediction, (ii) the radial orbital variations becomes more pronounced with the age of the stellar population and (iii) the effect of radial orbital variations on the metallicity gradients is minimal. The effect of radial orbital variations is found to be at most 6\% which does not statistically affect the radial gradient results. These findings contribute to a better understanding of the chemical evolution within the Galactic disc and provide an important basis for further research.
- [9] arXiv:2411.13666 [pdf, html, other]
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Title: Intrinsic and Environmental Effects on the Distribution of Star Formation in TNG100 GalaxiesComments: submitted to ApJ, revised in response to reviewer's comments 38 pages, 16 figures in main text; 3 appendices with 20 pages, 17 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present radial profiles of luminosity-weighted age, $age_L$, and $\Delta \Sigma_{SFR}$ for various populations of high- and low- mass central and satellite galaxies in the TNG100 cosmological simulation. Using these profiles, we investigate the impact of intrinsic and environmental factors on the radial distribution of star formation. For both central galaxies and satellites, we investigate the effects of black hole mass, cumulative AGN feedback energy, morphology, halo mass, and local galaxy overdensity on the profiles. In addition, we investigate the dependence of radial profiles of the satellite galaxies as a function of the redshifts at which they joined their hosts, as well as the net change in star-forming gas mass since the satellites joined their host. We find that high-mass ($M_*>10^{10.5} M_{\odot}$) central and satellite galaxies show evidence of inside-out quenching driven by AGN feedback. Effects from environmental processes only become apparent in averaged profiles at extreme halo masses and local overdensities. We find that the dominant quenching process for low-mass galaxies ($M_*<10^{10} M_{\odot}$) is environmental, generally occurring at low halo mass and high local galaxy overdensity for low-mass central galaxies and at high host halo masses for low-mass satellite galaxies. Overall, we find that environmental processes generally drive quenching from the outside-in.
- [10] arXiv:2411.13673 [pdf, html, other]
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Title: Detecting electromagnetic counterparts to LIGO/Virgo/KAGRA gravitational wave events with DECam: Neutron Star MergersKeerthi Kunnumkai, Antonella Palmese, Amanda M Farah, Mattia Bulla, Tim Dietrich, Peter T H Pang, Shreya Anand, Igor Andreoni, Tomas Cabrera, Brendan O ConnorComments: 18 pages, 10 figures, 10 tablesSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
With GW170817 being the only multimessenger gravitational wave (GW) event with an associated kilonova (KN) detected so far, there exists a pressing need for realistic estimation of the GW localization uncertainties and rates, as well as optimization of available telescope time to enable the detection of new KNe. For this purpose, we simulate GW events assuming a data-driven, GW-motivated distribution of binary parameters for the LIGO/Virgo/KAGRA (LVK) fourth and fifth observing runs (O4 and O5). For our particular case of estimating KN detection rates in the O4 and O5 runs, we map the binary neutron star (BNS) and neutron star-black hole (NSBH) properties to the optical light curves arising from r-process nucleosynthesis in the ejecta. We use the simulated population of KNe to generate follow-up observing plans, with the primary goal of optimizing detection with the Gravitational Wave Multi-Messenger Astronomy DECam Survey (GW-MMADS). We explore KN detectability as a function of mass, distance, and spin of the binaries. Out of the mergers that produce a KN in our simulations, we expect detectable KNe for DECam-like instruments at a per-year rate of: $1-16$ ($0-1$) for BNS (NSBH) in O4, and $16-165$ ($1-12$) for BNS (NSBH) in O5, using a fiducial exposure time and conditional on the uncertainty on the equation of state (EOS) and volumetric rates of the mergers. Taking into account observability constraints, our scheduler covers the location of the KN $\sim 30-38\%$ of the times for our fiducial EOS. We provide the depths needed to detect a significant fraction of our simulated mergers for the astronomical community to use in their follow-up campaigns.
- [11] arXiv:2411.13675 [pdf, html, other]
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Title: Asymmetry of the tidal tails of open star clusters in direct N-body integrations in Milgrom-law dynamicsComments: accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
Numerical QUMOND-simulations of star clusters orbiting in a Galactic disk potential show that the leading tidal arm of open star clusters contains tendentially more members than the trailing arm. However, these type of simulations are performed by solving the field-equations of QUMOND and already become non-practical for star cluster masses at around 5000 Msun. Nearby star clusters have masses of 1000 Msun or ~1000 particles and less/fewer and can currently not be simulated reliably in field-theoretical formulations of MOND. In order to handle particle numbers below the QUMOND-limit the star cluster is simulated in Milgrom-law dynamics (MLD): Milgrom's law is postulated to be valid for discrete systems in vectorial form. In order to suppress the Newtonisation of compact subsystems in the star cluster the gravitational force is softened below particle distances of 0.001 pc ~206 AU. Thus, MLD can only be considered as an approximation of a full MOND-theoretical description of discrete systems which are internally in the MOND regime. The MLD equations of motion are integrated by the standard Hermite scheme generally applied to Newtonian N-body systems, which is extended to solve for the accelerations and jerks associated with Milgrom's law. It is found that the tidal tails of a low-mass star cluster are populated asymmetrically in the MLD-treatment, very similar to the QUMOND simulations of the higher-mass star clusters. In the MLD-simulations the leading tail hosts up to twice as many members than the trailing arm and the low-mass open star cluster dissolves approximately 25% faster than in the respective Newtonian case.
- [12] arXiv:2411.13686 [pdf, html, other]
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Title: Chemical evolution of an evaporating lava poolComments: Accepted for publication in MNRAs. 19 pages, 15 figuresSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Many known rocky exoplanets are so highly irradiated that their dayside surfaces are molten, and `silicate atmospheres', composed of rock-forming elements, are generated above these lava pools. The compositions of these `lava planet' atmospheres are of great interest because they must be linked to the composition of the underlying rocky interiors. It may be possible to investigate these atmospheres, either by detecting them directly via emission spectroscopy or by observing the dust tails which trail the low mass `catastrophically evaporating planets'. In this work, we develop a simple chemical model of the lava pool--atmosphere system under mass loss, to study its evolution. Mass loss can occur both into space and from the day to the nightside. We show that the system reaches a steady state, where the material in the escaping atmosphere has the same composition as that melted into the lava pool from the mantle. We show that the catastrophically evaporating planets are likely to be in this evolved state. This means that the composition of their dust tails is likely to be a direct trace of the composition of the mantle material that is melted into the lava pool. We further show that, due to the strength of day-to-nightside atmospheric transport, this evolved state may even apply to relatively high-mass planets (>1 Earth Mass). Moreover, the low pressure of evolved atmospheres implies that non-detections may not be due to the total lack of an atmosphere. Both conclusions are important for the interpretation of future observations.
- [13] arXiv:2411.13698 [pdf, html, other]
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Title: GA-NIFS: A galaxy-wide outflow in a Compton-thick mini-BAL quasar at z = 3.5 probed in emission and absorptionMichele Perna, Santiago Arribas, Xihan Ji, Cosimo Marconcini, Isabella Lamperti, Elena Bertola, Chiara Circosta, Francesco D'Eugenio, Hannah Übler, Torsten Böker, Roberto Maiolino, Andrew J. Bunker, Stefano Carniani, Stéphane Charlot, Chris J. Willott, Giovanni Cresci, Eleonora Parlanti, Bruno Rodríguez Del Pino, Jan Scholtz, Giacomo VenturiComments: 18 pages, 13 figures, submitted to Astronomy & Astrophysics. Comments are welcomeSubjects: Astrophysics of Galaxies (astro-ph.GA)
Studying the distribution and properties of ionised gas in outflows driven by AGN is crucial for understanding the feedback mechanisms at play in extragalactic environments. In this study, we explore the connection between ionised outflows traced by rest-frame UV absorption and optical emission lines in GS133, a Compton thick AGN at z = 3.47. We combine observations from the JWST NIRSpec Integral Field Spectrograph (IFS) with archival VLT VIMOS long-slit spectroscopic data, as part of the GA-NIFS project. We perform a multi-component kinematic decomposition of the UV and optical line profiles to derive the physical properties of the absorbing and emitting gas in GS133. Our kinematic decomposition reveals two distinct components in the optical lines. The first component likely traces a rotating disk with a dynamical mass of 2e10 Msun. The second component corresponds to a galaxy-wide, bi-conical outflow, with a velocity of 1000 km/s and an extension of 3 kpc. The UV absorption lines show two outflow components, with bulk velocities v_out = -900 km/s and -1900 km/s, respectively. This characterises GS133 as a mini-BAL system. Balmer absorption lines with similar velocities are tentatively detected in the NIRSpec spectrum. Both photoionisation models and outflow energetics suggest that the ejected absorbing gas is located at 1-10 kpc from the AGN. We use 3D gas kinematic modelling to infer the orientation of the [O III] bi-conical outflow, and find that a portion of the emitting gas resides along our line of sight, suggesting that [O III] and absorbing gas clouds are partially mixed in the outflow. The derived mass-loading factor (i.e. the mass outflow rate divided by the SFR) of 1-10, and the kinetic coupling efficiency (i.e. the kinetic power divided by LAGN) of 0.1-1% per cent suggest that the outflow in GS133 provides significant feedback on galactic scales.
- [14] arXiv:2411.13701 [pdf, html, other]
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Title: Revisiting Constraints on Resonant Axion-Photon Conversions from CMB Spectral DistortionsComments: 18 pages, 14 figures, comments welcome!Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Axions and axion-like particles (ALPs) remain highly motivated extensions to the standard model due to their ability to address open questions such as the relic abundance of dark matter and the strong CP problem. Axions are also capable of undergoing a resonant mixing with photons when the masses of the two fields are roughly equal, producing a wide array of phenomenological consequences. Here, we revisit constraints coming from conversions of the cosmic microwave background (CMB) into axions, which will induce a distortion to the frequency spectrum of the background photons. We introduce a more detailed description for the modeling of the plasma mass of the photon, showcasing how the inclusion of Helium recombination can alter the conversion probability for photons in the Wien tail. Our results include an updated analytic framework, which allows us to define the precise spectral shape of the axion distortion, as well as a numeric component which utilized the code \texttt{CosmoTherm} to fully characterize the distortion, providing a slight increase in the constraining power over the analytics. We also treat for the first time the large-distortion regime for resonant axion-photon conversions. Under the assumption of large-scale primordial magnetic fields near the limit obtained from CMB observations, we find that spectral distortions can probe previously unexplored regions of the axion parameter space.
- [15] arXiv:2411.13709 [pdf, other]
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Title: The MICADO first light imager for the ELT: Testing the Lyot coronograph prototypesComments: 9 pagesJournal-ref: SPIE Proceedings #13097, 2024Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
MICADO, the European Extremely Large Telescope first light imager will feature a dedicated high contrast imaging mode specifically designed for observing and characterizing exoplanets and circumstellar disks. Its improved sensitivity and angular resolution, compared to existing instruments will significantly increase our knowledge on these planetary systems. MICADO will include three classical Lyot coronagraphs, one vector phase-apodized pupil plane (vAPP) and two sparse apertures. After rapidly describing the final design of MICADO high contrast mode, we will describe the current state of development of the coronographic components and the testing of the first Lyot coronagraph prototypes.
- [16] arXiv:2411.13718 [pdf, html, other]
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Title: The Decline and Fall of ROME. V. A Preliminary Search for Star-Disrupted Planet Interactions and Coronal Activity at 5 GHz Among White Dwarfs within 25 pcMatthew Route (1) ((1) Purdue University)Comments: 14 pages, 3 tables, 2 figures. Summary presented at the 56th Annual Meeting of the AAS Division for Planetary Sciences, abstract 407.04. In press at The Astrophysical JournalSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
The recent discovery of planetesimals orbiting white dwarfs has renewed interest in the final chapters of the evolution of planetary systems. Although observational and theoretical studies have examined the dynamical evolution of these systems, studies of their magnetic star-planet interactions, as powered by unipolar induction, have thus far only been assessed theoretically. This fifth paper of the ROME (Radio Observations of Magnetized Exoplanets) series presents the results of a targeted mini-survey of nine white dwarfs within 25 pc without known stellar mass companions in search of radio emissions generated by magnetic interactions between white dwarfs and their planetary remnants. This $\sim$5 GHz Arecibo radio telescope survey achieved mJy-level sensitivity over $<$1 s integration times. Although no exoplanet-induced stellar radio flares were detected, this is the first survey to search for magnetic star-planet interactions between white dwarfs and planetary companions, cores, or disrupted planetesimals. It is also the most extensive and sensitive radio survey for intrinsic coronal emissions from apparently isolated white dwarfs. The study of radio emissions from white dwarf systems may present a new means to detect and measure DC and DQ magnetic fields, search for white dwarf coronae, characterize the density and spatial distribution of white dwarf magnetospheric plasma, characterize the dynamical and electrical properties of planetary cores, and offer new constraints on the modeling of double degenerate merger events.
- [17] arXiv:2411.13746 [pdf, html, other]
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Title: Polarization effects on high contrast imaging: measurements on THD2 BenchComments: 13 pages, SPIE Proceedings of the 13092 conferenceJournal-ref: SPIE Proceedings, 2024Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
The spectroscopic study of mature giant planets and low mass planets (Neptune-like, Earth-like) requires instruments capable of achieving very high contrasts ($10^{-10}-10^{-11}$) at short angular separations. To achieve such high performance on a real instrument, many limitations must be overcome: complex component defects (coronagraph, deformable mirror), optical aberrations and scattering, mechanical vibrations and drifts, polarization effects, etc.
To study the overall impact on a complete system representative of high contrast instruments, we have developed a test bench at Paris Observatory, called THD2. In this paper, we focus on the polarization effects that are present on the bench which creates differential aberrations between the two linear polarization states. We compare the recorded beam positions of the two polarization states with the predicted from the Goos-Hänchen and Imbert-Fedorov effects, both of which cause spatial shifts and angular deviations of the beam, longitudinal and transverse respectively. Although these effects have already been studied in the literature from the optical and quantum mechanical points of view, their measurement and impact on a complete optical bench are rather rare, although they are crucial for high-contrast instruments.
After describing the Goos-Hänchen and Imbert-Fedorov effects and estimating their amplitude on the THD2 bench, we present the protocol we used to measure these effects of polarization on the light beam. We compare predictions and measurements and we conclude on the most limiting elements on our bench polarization-wise. - [18] arXiv:2411.13750 [pdf, html, other]
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Title: Radiation mechanism of twin kilohertz quasi-periodic oscillations in neutron star low mass X-ray binariesSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Context: The connection between quasi-periodic oscillations (QPOs) and magnetic fields has been investigated across various celestial bodies. Magnetohydrodynamics (MHD) waves have been employed to explain the simultaneous upper and lower kilohertz (kHz) QPOs. Nevertheless, the intricate and undefined formation pathways of twin kHz QPOs present a compelling avenue for exploration. This area of study holds great interest as it provides an opportunity to derive crucial parameters related to compact stars. Aims:We strives to develop a self-consistent model elucidating the radiation mechanism of twin kHz QPOs, subsequently comparing it with observations. Methods: A sample of 28 twin kHz QPOs observed from the X-ray binary 4U 1636--53 are used to compare with the results of the MCMC calculations according to our model of the radiation mechanism of twin kHz QPOs, which is related to twin MHD waves. Results: We obtain twenty-eight groups of parameters of 4U 1636--53 and a tight exponential fit between the flux and the temperature of seed photons to Compton up-scattering and find that the electron temperature in the corona around the neutron star decreases with the increasing temperature of the seed photons. Conclusions: The origin of twin kHz QPOs can be attributed to dual disturbances arising from twin MHD waves generated at the innermost radius of an accretion disc. The seed photons can be transported through a high temperature corona and Compton up-scattered. The variability of the photons with the frequencies of twin MHD waves can lead to the observed twin kHz QPOs.
- [19] arXiv:2411.13759 [pdf, html, other]
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Title: Photothermal Spectroscopy for Planetary Sciences: A Characterization of Planetary Materials in the Mid-IRComments: This paper follows, "Photothermal Spectroscopy for Planetary Sciences: Mid-IR Absorption Made Easy," (arXiv:2409.11626) and is part 2 of a series. This work catalogues O-PTIR Mid-IR measurements of various planetary materials. This is a pre-printSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Understanding of the formation and evolution of the Solar System requires understanding key and common materials found on and in planetary bodies. Mineral mixing and its implications on planetary body formation is a topic of high interest to the planetary science community. Previous work establishes a case for the use of Optical PhotoThermal InfraRed (O-PTIR) in planetary science and introduces and demonstrates the technique's capability to study planetary materials. In this paper, we performed a measurement campaign on granular materials relevant to planetary science, such as minerals found in lunar and martian soils. These laboratory measurements serve to start a database of O-PTIR measurements. We also present FTIR absorption measurements of the materials we observed in O-PTIR for comparison purposes. We find that the O-PTIR technique suffers from granular orientation effects similar to other IR techniques, but in most cases, is is directly comparable to commonly used absorption spectroscopy techniques. We conclude that O-PTIR would be an excellent tool for the purpose of planetary material identification during in-situ investigations on regolith and bedrock surfaces.
- [20] arXiv:2411.13790 [pdf, html, other]
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Title: Compton scattering in the optically thick uniform spherical corona around the neutron star in an X-ray binary in two conditionsSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We consider the Compton scattering in the optically thick uniform spherical corona around a neutron star in an X-ray binary. In the scattering, the low energy seed photons (0.1 - 2.5 keV) are scattered in low energy electrons (2.5 - 10 keV) in the corona in two conditions, i.e. initial seed photons are scattered in a whole corona and scattered in every layer of the corona that are supposed to be divided into many this http URL the same number of input seed photons, the same corona parameters and the same energy distribution of all photons in the two conditions are considered, the approximately same number of output photons can be obtained, which means that there is approximately a transform invariance of layering the Comptonized corona. Thus the scattering in the layers of a multi-layered corona is approximately equal to the scattering in the whole corona by dividing the whole corona into several this http URL means that Compton scattering for the initial seed photons scattered in a whole optically thick spherical corona with uniformly distributed electrons also can be considered as that the multiple Compton scatterings take place in the layers of a multi-layered corona in order approximately, which can be used to explore some physical process in one part of a corona.
- [21] arXiv:2411.13793 [pdf, html, other]
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Title: Unveiling the nature of the knee in the cosmic ray energy spectrumComments: 29 pages,8 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The knee-like structure around 4 PeV is the most striking feature in the cosmic ray energy spectrum, whose origin remains enigmatic. We propose a novel concept of the total logarithmic mass energy spectrum to characterize the knee, taking into account LHAASO measurements of the all-particle energy spectrum and the mean logarithmic mass. The predominant role of proton in the knee formation is unearthed. The case of a mass-dependent knee is ruled out with a significance of 22.9${\sigma}$ and the rigidity-dependent knee feature is revealed. An ankle-like structure stemming from the excess of iron is discovered at 9.7${\pm}$ 0.2 PeV with a significance of 25.9${\sigma}$. Our findings pierce the mist of the puzzling knee for the first time since its discovery.
- [22] arXiv:2411.13816 [pdf, html, other]
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Title: Constraints on primordial black holes from the observed number of Icarus-like ultrahigh magnification eventsComments: 9 pages, 3 figures, submitted to PRDSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Icarus is an individual star observed near the macro-critical curve of the MACS J1149 cluster, with the magnification factor estimated to be an order of thousands. Since microlenses near the macro-critical curve influence the number of such high-magnification events, the observed occurrence of Icarus-like events is expected to provide a useful constraint on the properties of microlenses. We first study the mass and mass fraction of microlenses consistent with the observed number of events assuming a single microlens component with a monochromatic mass function, finding that stars that contribute to the intracluster light (ICL) are consistent at the 95% confidence level. We then consider the contribution of primordial black holes (PBHs), which are one of the alternatives to the standard cold dark matter, as microlenses in addition to ICL stars. The derived parameter space indicates that a large abundance of PBHs with a mass around $1\ M_{\odot}$ and a fraction of PBHs to the total dark matter of $f_{\rm PBH} \gtrsim 0.2$ cannot explain the observed number of Icarus-like events and therefore is excluded. The methodology developed in this paper can be used to place tighter constraints on the fraction of PBHs from ongoing and future observations of ultrahigh magnification events.
- [23] arXiv:2411.13825 [pdf, html, other]
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Title: Planets Around Solar Twins/Analogs (PASTA) I.: High precision stellar chemical abundance for 17 planet-hosting stars and the condensation temperature trendQinghui Sun, Sharon Xuesong Wang, Tianjun Gan, Chenyang Ji, Zitao Lin, Yuan-Sen Ting, Johanna Teske, Haining Li, Fan Liu, Xinyan Hua, Jiaxin Tang, Jie Yu, Jiayue Zhang, Mariona Badenas-Agusti, Andrew Vanderburg, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Jon M. Jenkins, Richard P. Schwarz, Tristan Guillot, Thiam-Guan Tan, Dennis M. Conti, Kevin I. Collins, Gregor Srdoc, Chris Stockdale, Olga Suarez, Roberto Zambelli, Don Radford, Khalid Barkaoui, Phil Evans, Allyson BierylaComments: 26 pages, 10 figures, 7 tables; accepted for publication in ApJSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
The Sun is depleted in refractory elements compared to nearby solar twins, which may be linked to the formation of giant or terrestrial planets. Here we present high-resolution, high signal-to-noise spectroscopic data for 17 solar-like stars hosting planets, obtained with Magellan II/MIKE, to investigate whether this depletion is related to planet formation. We derive stellar parameters, including stellar atmosphere, age, radius, mass, and chemical abundances for 22 elements from carbon to europium through line-by-line differential analysis. Our uncertainties range from 0.01 dex for Fe and Si to 0.08 dex for Sr, Y, and Eu. By comparing the solar abundances to those of the 17 stars, we investigate the differential abundance ([X/Fe]$_{\rm solar}$ - [X/Fe]$_{\rm star}$) versus condensation temperature ($T_c$) trend. In particular, we apply Galactic chemical evolution corrections to five solar twins within the full sample. Our results conform to previous studies that the Sun is relatively depleted in refractory compared to volatile elements. For both five solar twins and the rest of solar-like stars, we find that all stars hosting known gas giant planets exhibit negative $T_c$ trend slopes, suggesting that the Sun is relatively depleted in refractory elements compared to similar giant-planet-host stars. Additionally, we find no correlation between $T_c$ trend slopes and the total mass of detected terrestrial planets in each system, suggesting that terrestrial planet formation may not be the cause of refractory element depletion in the Sun.
- [24] arXiv:2411.13839 [pdf, html, other]
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Title: Theoretical Studies on the Evolution of Solar Filaments in Response to New Emerging FluxComments: 18 pages, 7 figures, accepted by ApJLSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
New emerging flux (NEF) has long been considered a mechanism for solar eruptions, but detailed process remains an open question. In this work, we explore how NEF drives a coronal magnetic configuration to erupt. This configuration is created by two magnetic sources of strengths $M$ and $S$ embedded in the photosphere, one electric-current-carrying flux rope (FR) floating in the corona, and an electric current induced on the photospheric surface by the FR. The source $M$ is fixed accounting for the initial background field, and $S$ changes playing the role of NEF. We introduce the channel function $C$ to forecast the overall evolutionary behavior of the configuration. Location, polarity, and strength of NEF governs the evolutionary behavior of FR before eruption. In the case of $|S/M|<1$ with reconnection occur between new and old fields, the configuration in equilibrium evolves to the critical state, invoking the catastrophe. In this case, if polarities of the new and old fields are opposite, reconnection occurs as NEF is close to FR; and if polarities are the same, reconnection happens as NEF appears far from FR. With different combinations of the relative polarity and the location, the evolutionary behavior of the system gets complex, and the catastrophe may not occur. If $|S/M|>1$ and the two fields have opposite polarity, the catastrophe always takes place; but if the polarities are the same, catastrophe occurs only as NEF is located far from FR; otherwise, the evolution ends up either with failed eruption or without catastrophe at all.
- [25] arXiv:2411.13870 [pdf, html, other]
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Title: G321.93-0.01: A Rare Site of Multiple Hub-Filament Systems with Evidence of Collision and Merging of FilamentsA. K. Maity, L. K. Dewangan, N. K. Bhadari, Y. Fukui, A. Haj Ismail, O. R. Jadhav, Saurabh Sharma, H. SanoComments: Accepted for publication in The Astronomical Journal, the manuscript consists of 27 pages, 11 figures, and 5 tablesSubjects: Astrophysics of Galaxies (astro-ph.GA)
Hub-filament systems (HFSs) are potential sites of massive star formation (MSF). To understand the role of filaments in MSF and the origin of HFSs, we conducted a multi-scale and multi-wavelength observational investigation of the molecular cloud G321.93-0.01. The $^{13}$CO($J$ = 2-1) data reveal multiple HFSs, namely, HFS-1, HFS-2, and a candidate HFS (C-HFS). HFS-1 and HFS-2 exhibit significant mass accretion rates ($\dot{M}_{||}$ $> 10^{-3}$ $M_{\odot}$ yr$^{-1}$) to their hubs (i.e., Hub-1 and Hub-2, respectively). Hub-1 is comparatively massive, having higher $\dot{M}_{||}$ than Hub-2, allowing to derive a relationship $\dot{M}_{||} \propto M^{\beta}_{\rm{hub}}$, with $\beta \sim1.28$. Detection of three compact HII regions within Hub-1 using MeerKAT 1.28 GHz radio continuum data and the presence of a clump (ATL-3), which meets Kauffmann & Pillai's criteria for MSF, confirm the massive star-forming activity in HFS-1. We find several low-mass ALMA cores (1-9 $M_{\odot}$) inside ATL-3. The presence of a compact HII region at the hub of C-HFS confirms that it is active in MSF. Therefore, HFS-1 and C-HFS are in relatively evolved stages of MSF, where massive stars have begun ionizing their surroundings. Conversely, despite a high $\dot{M}_{||}$, the non-detection of radio continuum emission toward Hub-2 suggests it is in the relatively early stages of MSF. Analysis of $^{13}$CO($J$ = 2-1) data reveals that the formation of HFS-1 was likely triggered by the collision of a filamentary cloud about 1 Myr ago. In contrast, the relative velocities ($\gtrsim 1$ km s$^{-1}$) among the filaments of HFS-2 and C-HFS indicate their formation through the merging of filaments.
- [26] arXiv:2411.13891 [pdf, html, other]
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Title: UPdec-Webb: A Dataset for Coaddition of JWST NIRCam ImagesLei Wang, Huanyuan Shan, Lin Nie, Cheng Cheng, Fang-Ting Yuan, Qifan Cui, Guoliang Li, Yushan Xie, Dezi Liu, Yao Liu, Min Fang, Nan Li, Peng Jia, Ran Li, Fengshan Liu, Yiping Shu, Chang Jiang, Cheng-Liang Wei, Han Qu, Wen-Wen Zheng, Li-Yan Zhu, Xi KangComments: 21 pages, 18 figures, accepted for publication in ApJSSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)
We present the application of the image coaddition algorithm, Up-sampling and PSF Deconvolution Coaddition (UPDC), for stacking multiple exposure images captured by the James Webb Space Telescope (JWST) Near-Infrared Camera (NIRCam). By addressing the point spread function (PSF) effect, UPDC provides visually enhanced and sharper images. Furthermore, the anti-aliasing and super-resolution capabilities of UPDC make it easier to deblend sources overlapped on images, yielding a higher accuracy of aperture photometry. We apply this algorithm to the SMACS J0723 imaging data. Comparative analysis with the Drizzle algorithm demonstrates significant improvements in detecting faint sources, achieving accurate photometry, and effectively deblending (super-resolution) closely packed sources. {As a result, we have newly detected a pair of close binary stars that were previously unresolvable in the original exposures or the Drizzled image.} These improvements significantly benefit various scientific projects conducted by JWST. The resulting dataset, named "UPdec-Webb", can be accessible through the official website of the Chinese Virtual Observatory (ChinaVO).
- [27] arXiv:2411.13925 [pdf, html, other]
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Title: Nonlinear internal waves breaking in stellar radiation zones. Parametrisation for the transport of angular momentum: bridging geophysical to stellar fluid dynamicsComments: 9 pages, 1 figure, accepted for publication in Astronomy & AstrophysicsSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (physics.ao-ph)
Internal gravity waves (hereafter IGWs) are one of the mechanisms that can play a key role to redistribute efficiently angular momentum in stars along their evolution. The study of IGWs is thus of major importance since space-based asteroseismology reveals a transport of angular momentum in stars, which is stronger by two orders of magnitude than the one predicted by stellar models ignoring their action or those of magnetic fields. IGWs trigger angular momentum transport when they are damped by heat or viscous diffusion, when they meet a critical layer or when they break. Theoretical prescriptions have been derived for the transport of angular momentum induced by IGWs because of their radiative and viscous dampings and of the critical layers they encounter along their propagation. However, none has been proposed for the transport triggered by their nonlinear breaking. In this work, we aim to derive such a physical and robust prescription, which can be implemented in stellar structure and evolution codes. We adapt an analytical saturation model, which has been developed for IGWs nonlinear convective breaking in the Earth atmosphere and has been successfully compared to in-situ measurements in the stratosphere, to the case of deep spherical stellar interiors. In a first step, we neglect the modification of IGWs by the Coriolis acceleration and the Lorentz force, which are discussed and taken into account in a second step. We derive a complete semi-analytical prescription for the transport of angular momentum by IGWs, which takes into account both their radiative damping and their potential nonlinear breaking because of their convective and vertical shear instabilities. This allows us to bring the physical prescription for the interactions between IGWs and the differential rotation to the same level of realism that the one used in global circulation models for the atmosphere.
- [28] arXiv:2411.13960 [pdf, html, other]
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Title: Learning the Universe: Cosmological and Astrophysical Parameter Inference with Galaxy Luminosity Functions and ColoursChristopher C. Lovell, Tjitske Starkenburg, Matthew Ho, Daniel Anglés-Alcázar, Romeel Davé, Austen Gabrielpillai, Kartheik Iyer, Alice E. Matthews, William J. Roper, Rachel Somerville, Laura Sommovigo, Francisco Villaescusa-NavarroComments: 28 pages, 20 figures, submitted to MNRAS. Comments and feedback welcome!Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We perform the first direct cosmological and astrophysical parameter inference from the combination of galaxy luminosity functions and colours using a simulation based inference approach. Using the Synthesizer code we simulate the dust attenuated ultraviolet--near infrared stellar emission from galaxies in thousands of cosmological hydrodynamic simulations from the CAMELS suite, including the Swift-EAGLE, Illustris-TNG, Simba & Astrid galaxy formation models. For each galaxy we calculate the rest-frame luminosity in a number of photometric bands, including the SDSS $\textit{ugriz}$ and GALEX FUV & NUV filters; this dataset represents the largest catalogue of synthetic photometry based on hydrodynamic galaxy formation simulations produced to date, totalling >200 million sources. From these we compile luminosity functions and colour distributions, and find clear dependencies on both cosmology and feedback. We then perform simulation based (likelihood-free) inference using these distributions, and obtain constraints on both cosmological and astrophysical parameters. Both colour distributions and luminosity functions provide complementary information on certain parameters when performing inference. Most interestingly we achieve constraints on $\sigma_8$, describing the clustering of matter. This is attributable to the fact that the photometry encodes the star formation--metal enrichment history of each galaxy; galaxies in a universe with a higher $\sigma_8$ tend to form earlier and have higher metallicities, which leads to redder colours. We find that a model trained on one galaxy formation simulation generalises poorly when applied to another, and attribute this to differences in the subgrid prescriptions, and lack of flexibility in our emission modelling. The photometric catalogues are publicly available at: this https URL .
- [29] arXiv:2411.13968 [pdf, html, other]
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Title: Reverse Shock Emission from Misaligned Structured Jets in Gamma-Ray BurstsComments: 21 pages, 12 figures and 3 tables. Accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The afterglow of gamma-ray bursts (GRBs) has been extensively discussed in the context of shocks generated during an interaction of relativistic outflows with their ambient medium. This process leads to the formation of both a forward and a reverse shock. While the emission from the forward shock, observed off-axis, has been well-studied as a potential electromagnetic counterpart to a gravitational wave-detected merger, the contribution of the reverse shock is commonly overlooked. In this paper, we investigate the contribution of the reverse shock to the GRB afterglows observed off-axis. In our analysis, we consider jets with different angular profiles, including two-component jets, power-law structured jets, Gaussian jets and 'mixed jets' featuring a Poynting-flux-dominated core surrounded by a baryonic wing. We apply our model to GRB 170817A/GW170817 and employ the Markov Chain Monte Carlo (MCMC) method to obtain model parameters. Our findings suggest that the reverse shock emission can significantly contribute to the early afterglow. In addition, our calculations indicate that the light curves observable in future off-axis GRBs may exhibit either double peaks or a single peak with a prominent feature, depending on the jet structure, viewing angle and micro-physics shock parameters.
- [30] arXiv:2411.13973 [pdf, html, other]
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Title: 3D Localization of FRB 20190425A for Its Potential Host Galaxy and ImplicationsComments: 19 pages, 10 figures, 3 tablesSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA)
Fast radio bursts (FRBs) are high-energy, short-duration phenomena in radio astronomy. Identifying their host galaxies can provide insights into their mysterious origins. In this paper, we introduce a novel approach to identifying potential host galaxies in three-dimensional space. We use FRB 20190425A and GW190425 as an example to illustrate our method. Recently, due to spatial and temporal proximity, the potential association of GW190425 with FRB 20190425A has drawn attention, leading to the identification of a likely host galaxy, UGC 10667, albeit without confirmed kilonova emissions. We search for the host galaxy of FRB 20190425A with a full CHIME localization map. Regardless of the validity of the association between GW190425 and FRB 20190425A, we identify an additional potential host galaxy (SDSS J171046.84+212732.9) from the updated GLADE galaxy catalog, supplementing the importance of exploring the new volume. We employed various methodologies to determine the most probable host galaxy of GW190424 and FRB 20190425A, including a comparison of galaxy properties and constraints on their reported observation limits using various Kilonova models. Our analysis suggests that current observations do not definitively identify the true host galaxy. Additionally, the Kilonova models characterized by a gradual approach to their peak are contradicted by the observational upper limits of both galaxies. Although the absence of optical emission detection raises doubts, it does not definitively disprove the connection between GW and FRB.
- [31] arXiv:2411.13991 [pdf, html, other]
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Title: Collisional damping in debris discs: Only significant if collision velocities are lowComments: pre-print of article published in Astronomy & Astrophysics, DOI: this https URL output data DOI: this https URLJournal-ref: A&A, 691, A302 (2024)Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Context. Dusty debris discs around main sequence stars are observed to vary widely in terms of their vertical thickness. Their vertical structure may be affected by damping in inelastic collisions. Although kinetic models have often been used to study the collisional evolution of debris discs, these models have not yet been used to study the evolution of their vertical structure. Aims. We extend an existing implementation of a kinetic model of collisional evolution to include the evolution of orbital inclinations and we use this model to study the effects of collisional damping in pre-stirred discs. Methods. We evolved the number of particles of different masses, eccentricities, and inclinations using the kinetic model and used Monte Carlo simulations to calculate collision rates between particles in the disc. We considered all relevant collisional outcomes including fragmentation, cratering, and growth. Results. Collisional damping is inefficient if particles can be destroyed by projectiles that are of much lower mass. If that is the case, catastrophic disruptions shape the distributions of eccentricities and inclinations, and their average values evolve slowly and at the same rate for all particle sizes. Conclusions. The critical projectile-to-target mass ratio (Yc) and the collisional timescale jointly determine the level of collisional damping in debris discs. If Yc is much smaller than unity, a debris disc retains the inclination distribution that it is born with for much longer than the collisional timescale of the largest bodies in the disc. Such a disc should exhibit a vertical thickness that is independent of wavelength even in the absence of other physical processes. Collisional damping is efficient if Yc is of order unity or larger. For millimetre-sized dust grains and common material strength assumptions, this requires collision velocities of lower than ~40 m/s. Abridged
- [32] arXiv:2411.14040 [pdf, html, other]
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Title: Unsupervised Machine Learning for Classifying CHIME Fast Radio Bursts and Investigating Empirical RelationsComments: 17 pages, 8 pages, 3 tablesSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Fast Radio Bursts (FRBs) are highly energetic millisecond-duration astrophysical phenomena typically categorized as repeaters or non-repeaters. However, observational limitations may lead to misclassifications, suggesting a larger proportion of repeaters than currently identified. In this study, we leverage unsupervised machine learning techniques to classify FRBs using data from the CHIME/FRB catalog, including both the first catalog and a recent repeater catalog. By employing Uniform Manifold Approximation and Projection (UMAP) for dimensionality reduction and clustering algorithms (k-means and HDBSCAN), we successfully segregate repeaters and non-repeaters into distinct clusters, identifying over 100 potential repeater candidates. Our analysis reveals several empirical relations within the clusters, including the ${\rm log \,}\Delta t_{sc} - {\rm log \,}\Delta t_{rw}$, ${\rm log \,}\Delta t_{sc} - {\rm log \,}T_B$, and $r - \gamma$ correlations, which provide new insights into the physical properties and emission mechanisms of FRBs. This study demonstrates the effectiveness of unsupervised learning in classifying FRBs and identifying potential repeaters, paving the way for more precise investigations into their origins and applications in cosmology. Future improvements in observational data and machine learning methodologies are expected to further enhance our understanding of FRBs.
- [33] arXiv:2411.14056 [pdf, html, other]
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Title: First Calculations of Starspot Spectra based on 3D Radiative Magnetohydrodynamics SimulationsH. N. Smitha, Alexander I. Shapiro, Veronika Witzke, Nadiia M. Kostogryz, Yvonne C. Unruh, Tanayveer S. Bhatia, Robert Cameron, Sara Seager, Sami K. SolankiComments: Accepted for publication in the Astrophysical Journal LettersSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Accurate calculations of starspot spectra are essential for multiple applications in astronomy. The current standard is to represent starspot spectra by spectra of stars that are cooler than the quiet star regions. This implies approximating a starspot as a non-magnetic 1D structure in radiative-convective equilibrium, parametrizing convective energy transport by mixing length theory. It is the inhibition of convection by the starspot magnetic field that is emulated by using a lower spot temperature relative to the quiet stellar regions. Here, we take a different approach avoiding the approximate treatment of convection and instead self-consistently accounting for the interaction between matter, radiation, and the magnetic field. We simulate spots on G2V, K0V, M0V stars with the 3D radiative magnetohydrodynamics code MURaM and calculate spectra ($R \approx 500$ from 250~nm to 6000~nm) using ray-by-ray radiative transfer with the MPS-ATLAS code. We find that the 1D models fail to return accurate umbral and penumbral spectra on K0V and M0V stars where convective and radiative transfer of energy is simultaneously important over a broad range of atmospheric heights rendering mixing length theory inaccurate. However, 1D models work well for G2V stars, where both radiation and convection significantly contribute to energy transfer only in a narrow region near the stellar surface. Quantitatively, the 1D approximation leads to errors longward of 500 nm of about 50\% for both umbral and penumbral flux contrast relative to quiet star regions on M0V stars, and less than 2\% (for umbrae) and 10\% (for penumbrae) for G2V stars.
- [34] arXiv:2411.14078 [pdf, html, other]
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Title: Self-supervised learning for radio-astronomy source classification: a benchmarkThomas Cecconello, Simone Riggi, Ugo Becciano, Fabio Vitello, Andrew M. Hopkins, Giuseppe Vizzari, Concetto Spampinato, Simone PalazzoSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Computer Vision and Pattern Recognition (cs.CV)
The upcoming Square Kilometer Array (SKA) telescope marks a significant step forward in radio astronomy, presenting new opportunities and challenges for data analysis. Traditional visual models pretrained on optical photography images may not perform optimally on radio interferometry images, which have distinct visual characteristics.
Self-Supervised Learning (SSL) offers a promising approach to address this issue, leveraging the abundant unlabeled data in radio astronomy to train neural networks that learn useful representations from radio images. This study explores the application of SSL to radio astronomy, comparing the performance of SSL-trained models with that of traditional models pretrained on natural images, evaluating the importance of data curation for SSL, and assessing the potential benefits of self-supervision to different domain-specific radio astronomy datasets.
Our results indicate that, SSL-trained models achieve significant improvements over the baseline in several downstream tasks, especially in the linear evaluation setting; when the entire backbone is fine-tuned, the benefits of SSL are less evident but still outperform pretraining. These findings suggest that SSL can play a valuable role in efficiently enhancing the analysis of radio astronomical data. The trained models and code is available at: \url{this https URL} - [35] arXiv:2411.14149 [pdf, other]
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Title: X-Shooting ULLYSES: Massive Stars at Low Metallicity X. Physical Parameters and Feedback of Massive Stars in the LMC N11 B Star-Forming RegionV.M.A. Gómez-González, L.M. Oskinova, W.-R. Hamann, H. Todt, D. Pauli, S. Reyero Serantes, M. Bernini-Peron, A.C. Sander, V. Ramachandran, J.S. Vink, P.A. Crowther, S.R. Berlanas, A. ud-Doula, A.C. Gormaz-Matamala, C. Kehrig, R. Kuiper, C. Leitherer, L. Mahy, A.F. McLeod, A. Mehner, N. Morrell, T. Shenar, O.G. Telford, J. Th. van Loon, F. Tramper, A. WoffordComments: Accepted in Astronomy and AstrophysicsSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
Massive stars lead the ionization and mechanical feedback within young star-forming regions. The Large Magellanic Cloud (LMC) is an ideal galaxy for studying individual massive stars and quantifying their feedback contribution to the environment. We analyze eight exemplary targets in LMC N11 B from the Hubble UV Legacy Library of Young Stars as Essential Standards (ULLYSES) program, using novel spectra from HST (COS and STIS) in the UV, and from VLT (X-shooter) in the optical. We model the spectra of early to late O-type stars by using state-of-the-art PoWR atmosphere models. We determine the stellar and wind parameters (e.g., $T_\star$, $\log g$, $L_{\star}$, $\dot{M}$, $v_\infty$) of the analyzed objects, chemical abundances (C, N, O), ionizing and mechanical feedback ($Q_\mathrm{H}$, $Q_\mathrm{He{\small{I}}}$, $Q_\mathrm{He{\small{II}}}$, $L_\mathrm{mec}$) and X-rays. We report ages of $2-4.5$ Myr and masses of $30-60$ $M_\odot$ for the analyzed stars in N11 B, consistent with a scenario of sequential star formation. We note that the observed wind-momentum luminosity relation is consistent with theoretical predictions. We detect nitrogen enrichment in most of the stars, up to a factor of seven. However, we do not find a correlation between nitrogen enrichment and projected rotational velocity. Finally, based on their spectral type, we estimate the total ionizing photons injected from the O-type stars in N11 B into its environment. We report $\log$ ($\sum$ $Q_\mathrm{H}$)$=50.5$ ph s$^{-1}$, $\log$ ($\sum$ $Q_\mathrm{He{\small{I}}}$)$=49.6$ ph s$^{-1}$ and $\log$ ($\sum$ $Q_\mathrm{He{\small{II}}}$)$=44.4$ ph s$^{-1}$, consistent with the total ionizing budget in N11.
- [36] arXiv:2411.14150 [pdf, html, other]
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Title: Constraining the Binarity of Massive Black Holes in the Galactic Center and Some Nearby Galaxies via Pulsar Timing Array Observations of Gravitational WavesComments: 20 pages, 13 figures, accepted for publication in ApJSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
Massive black holes (MBHs) exist in the Galactic center (GC) and other nearby galactic nuclei. As natural outcome of galaxy mergers, some MBHs may have a black hole (BH) companion. In this paper, assuming that the MBHs in the GC and some nearby galaxies are in binaries with orbital periods ranging from months to years (gravitational-wave frequency $\sim1-100$\,nHz), we investigate the detectability of gravitational-waves from these binary MBHs (BBHs) and constraints on the parameter space for the existence of BBHs in the GC, LMC, M31, M32, and M87, that may be obtained by current/future pulsar timing array (PTA) observations. We find that a BBH in the GC, if any, can be revealed by the Square Kilometer Array PTA (SKA-PTA) if its mass ratio $q\gtrsim10^{-4}-10^{-3}$ and semimajor axis $a\sim20-10^3$\,AU. The existence of a BH companion of the MBH can be revealed by SKA-PTA with $\sim20$-year observations in M31 if $q\gtrsim10^{-4}$ and $a\sim10^2-10^4$\,AU or in M87 if $q\gtrsim10^{-5}$ and $a\sim10^3-2\times10^4$\,AU, but not in LMC and M32 if $q\ll1$. If a number of milli-second stable pulsars with distances $\lesssim0.1-1$\,pc away from the central MBH in the GC, LMC, M32, or M31, can be detected in future and applied to PTAs, the BH companion with mass even down to $\sim100M_\odot$, close to stellar masses, can be revealed by such PTAs. Future PTAs are expected to provide an independent way to reveal BBHs and low-mass MBH companions in the GC and nearby galaxies, improving our understandings of the formation and evolution of MBHs and galaxies.
- [37] arXiv:2411.14154 [pdf, html, other]
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Title: Determination of cosmic curvature independent of the sound horizon and $H_0$ using BOSS/eBOSS and DESI DR1 BAO observationsComments: 8 pages, 3 figures, comments are welcomeSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present an improved model-independent method for determining the cosmic curvature using the observations of Baryon Acoustic Oscillations (BAOs) and the Hubble parameter. The purpose of this work is to provide insights into late-universe curvature measurements using available observational data and techniques. Thus, we use two sources of BAO data sets, BOSS/eBOSS and latest DESI DR1, and two reconstruction methods, Gaussian process (GP) and artificial neural network (ANN). It is important to highlight that our method circumvents influence induced by the sound horizon in BAO observations and the Hubble constant. Combining BAO data from BOSS/eBOSS plus DESI DR1, we find that the constraint on the cosmic curvature results in $\Omega_K=-0.040^{+0.142}_{-0.145}$ with an observational uncertainty of $1\sigma$ in the framework of GP method. This result changes to $\Omega_K=-0.010^{+0.405}_{-0.424}$ when the ANN method is applied. Further comparative analysis of samples from two BAO data sources, we find that there is almost no difference between the two samples. Although the curvature values obtained from the data samples using DESI DR1 are on the slightly positive and the samples using BOSS/eBOSS are on the slightly negative, these results both report that our universe has a flat spatial curvature within uncertainties, and the precision of constraining the curvature with two BAO samples is almost equal.
- [38] arXiv:2411.14189 [pdf, html, other]
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Title: Reevaluating $H_0$ Tension with Non-Planck CMB and DESI BAO Joint AnalysisComments: 5 pages, 1 figure, 2 tablesSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
$H_0$ tension in the spatially flat $\Lambda$CDM model is reevaluated by employing three sets of non-Planck CMB data, namely WMAP, WMAP+ACT, and WMAP+SPT, in conjunction with DESI BAO data and non-DESI BAO datasets including 6dFGS, SDSS DR7, and SDSS DR16. Our analysis yields $H_0 = 68.86\pm 0.68~\mathrm{km\ s^{-1} Mpc^{-1}}$ with WMAP+DESI BAO, $H_0 = 68.72\pm 0.51~\mathrm{km\ s^{-1} Mpc^{-1}}$ with WMAP+ACT+DESI BAO, and $H_0 = 68.62\pm 0.52~\mathrm{km\ s^{-1} Mpc^{-1}}$ with WMAP+SPT+DESI BAO. The results of non-Planck CMB+DESI BAO exhibit a $3.4\sigma$, $3.7\sigma$, and $3.8\sigma$ tension with the SH0ES local measurement respectively which are around $1 \sigma$ lower in significance for the Hubble tension compared to Planck CMB+DESI BAO. Moreover, by combining DESI BAO data+non-Planck CMB measurements, we obtain a more stringent constraint on the Hubble constant compared to non-DESI BAO data+non-Planck CMB data, as well as reducing the significance of the Hubble tension.
- [39] arXiv:2411.14190 [pdf, html, other]
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Title: The Sun at millimeter wavelengths V. Magnetohydrodynamic waves in a fibrillar structureMaryam Saberi, Shahin Jafarzadeh, Sven Wedemeyer, Ricardo Gafeira, Mikolaj Szydlarski, David Jess, Marco StangaliniSubjects: Solar and Stellar Astrophysics (astro-ph.SR)
Magnetohydrodynamic (MHD) waves, playing a crucial role in transporting energy through the solar atmosphere, manifest in various chromospheric structures. Here, we investigated MHD waves in a long-lasting dark fibril using high-temporal-resolution (2~s cadence) Atacama Large Millimeter/submillimeter Array (ALMA) observations in Band 6 (centered at 1.25~mm). We detected oscillations in brightness temperature, horizontal displacement, and width at multiple locations along the fibril, with median periods and standard deviations of $240\pm114$~s, $225\pm102$~s, and $272\pm118$~s, respectively. Wavelet analysis revealed a combination of standing and propagating waves, suggesting the presence of both MHD kink and sausage modes. Less dominant than standing waves, oppositely propagating waves exhibit phase speeds (median and standard deviation of distributions) of $74\pm204$~km/s, $52\pm197$~km/s, and $28\pm254$~km/s for the three observables, respectively. This work demonstrates ALMA's capability to effectively sample dynamic fibrillar structures, despite previous doubts, and provides valuable insights into wave dynamics in the upper chromosphere.
- [40] arXiv:2411.14191 [pdf, html, other]
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Title: Post-processing subtraction of tilt-to-length noise in LISA in the presence of gravitational wave signalsSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc)
The Laser Interferometer Space Antenna (LISA) will be the first space-based gravitational wave (GW) observatory. It will measure gravitational wave signals in the frequency regime from 0.1 mHz to 1 Hz. The success of these measurements will depend on the suppression of the various instrument noises. One important noise source in LISA will be tilt-to-length (TTL) coupling. Here, it is understood as the coupling of angular jitter, predominantly from the spacecraft, into the interferometric length readout. The current plan is to subtract this noise in-flight in post-processing as part of a noise minimization strategy. It is crucial to distinguish TTL coupling well from the GW signals in the same readout to ensure that the noise will be properly modeled. Furthermore, it is important that the subtraction of TTL noise will not degrade the GW signals. In the present manuscript, we show on simulated LISA data and for four different GW signal types that the GW responses have little effect on the quality of the TTL coupling fit and subtraction. Also, the GW signal characteristics were not altered by the TTL coupling subtraction.
- [41] arXiv:2411.14209 [pdf, html, other]
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Title: Aeos: Transport of metals from minihalos following Population III stellar feedbackJennifer Mead, Kaley Brauer, Greg L. Bryan, Mordecai-Mark Mac Low, Alexander P. Ji, John H. Wise, Andrew Emerick, Eric P. Andersson, Anna Frebel, Benoit CôtéComments: 16 pages, 12 figures, 1 animated figure (see source files), submitted to ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
We investigate how stellar feedback from the first stars (Population III) distributes metals through the interstellar and intergalactic medium using the star-by-star cosmological hydrodynamics simulation, Aeos. We find that energy injected from the supernovae of the first stars is enough to expel a majority of gas and injected metals beyond the virial radius of halos with mass $M_* \lesssim 10^7$ M$_\odot$, regardless of the number of supernovae. This prevents self-enrichment and results in a non-monotonic increase in metallicity at early times. Most minihalos ($M \gtrsim 10^5 \, \rm M_\odot$) do not retain significant fractions of the yields produced within their virial radii until they have grown to halo masses of $M \gtrsim 10^7 \, \rm M_\odot$. The loss of metals to regions well beyond the virial radius delays the onset of enriched star formation and extends the period that Population III star formation can persist. We also explore the contributions of different nucleosynthetic channels to 10 individual elements. On the timescale of the simulation (lowest redshift $z=14.3$), enrichment is dominated by core-collapse supernovae for all elements, but with a significant contribution from asymptotic giant branch winds to the s-process elements, which are normally thought to only be important at late times. In this work, we establish important mechanisms for early chemical enrichment which allows us to apply Aeos in later epochs to trace the evolution of enrichment during the complete transition from Population III to Population II stars.
- [42] arXiv:2411.14218 [pdf, html, other]
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Title: A Comprehensive Hadronic Code Comparison for Active Galactic NucleiMatteo Cerruti, Annika Rudolph, Maria Petropoulou, Markus Böttcher, Stamatios I. Stathopoulos, Foteini Oikonomou, Stavros Dimitrakoudis, Anton Dmytriiev, Shan Gao, Susumu Inoue, Apostolos Mastichiadis, Kohta Murase, Anita Reimer, Joshua Robinson, Xavier Rodrigues, Andreas ZechComments: 32 pages; prepared for submission to AAS journalsSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
We perform the first dedicated comparison of five hadronic codes (AM$^3$, ATHE$\nu$A, B13, LeHa-Paris, and LeHaMoC) that have been extensively used in modeling of the spectral energy distribution (SED) of jetted active galactic nuclei. The purpose of this comparison is to identify the sources of systematic errors (e.g., implementation method of proton-photon interactions) and to quantify the expected dispersion in numerical SED models computed with the five codes. The outputs from the codes are first tested in synchrotron self-Compton scenarios that are the simplest blazar emission models used in the literature. We then compare the injection rates and spectra of secondary particles produced in pure hadronic cases with monoenergetic and power-law protons interacting on black-body and power-law photon fields. We finally compare the photon SEDs and the neutrino spectra for realistic proton-synchrotron and leptohadronic blazar models. We find that the codes are in excellent agreement with respect to the spectral shape of the photons and neutrinos. There is a remaining spread in the overall normalization that we quantify, at its maximum, at the level of $\pm 40\%$. This value should be used as an additional, conservative, systematic uncertainty term when comparing numerical simulations and observations.
- [43] arXiv:2411.14225 [pdf, other]
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Title: Reflected-light Phase Curves with PICASO: A Kepler-7b Case StudyColin D. Hamill, Alexandria V. Johnson, Natasha Batalha, Rowan Nag, Peter Gao, Danica Adams, Tiffany KatariaJournal-ref: Astrophysical Journal, 976, 181 (2024)Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Examining reflected light from exoplanets aids in our understanding of the scattering properties of their atmospheres and will be a primary task of future flagship space- and ground-based telescopes. We introduce an enhanced capability of Planetary Intensity Code for Atmospheric Scattering Observations (PICASO), an open-source radiative transfer model used for exoplanet and brown dwarf atmospheres, to produce reflected light phase curves from three-dimensional atmospheric models. Since PICASO is coupled to the cloud code Virga, we produce phase curves for different cloud condensate species and varying sedimentation efficiencies (fsed) and apply this new functionality to Kepler-7b, a hot Jupiter with phase curve measurements dominated by reflected starlight. We model three different cloud scenarios for Kepler-7b: MgSiO3 clouds only, Mg2SiO4 clouds only, and Mg2SiO4, Al2O3, and TiO2 clouds. All our Virga models reproduce the cloudy region west of the substellar point expected from previous studies, as well as clouds at high latitudes and near the eastern limb, which are primarily composed of magnesium silicates. Al2O3 and TiO2 clouds dominate near the substellar point. We then compare our modeled reflected light phase curves to Kepler observations and find that models with all three cloud condensate species and low sedimentation efficiencies (0.03 - 0.1) match best, though our reflected light phase curves show intensities approximately one-third of those observed by Kepler. We conclude that a better understanding of zonal transport, cloud radiative feedback, and particle scattering properties is needed to further explain the differences between the modeled and observed reflected light fluxes.
- [44] arXiv:2411.14231 [pdf, html, other]
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Title: Determining the absolute chemical abundance of nitrogen and sulfur in the quasar outflow of 3C298Comments: Accepted for publication in A&A- 11 pages, 10 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA)
Context. Quasar outflows are key players in the feedback processes that influence the evolution of galaxies and the intergalactic medium. The chemical abundance of these outflows provides crucial insights into their origin and impact. Aims. To determine the absolute abundances of nitrogen and sulfur and the physical conditions of the outflow seen in quasar 3C298. Methods. We analyze archival spectral data from the Hubble Space Telescope (HST) for 3C298. We measure Ionic column densities from the absorption troughs and compare the results to photoionization predictions made by the Cloudy code for three different spectral energy distributions (SED), including MF87, UVsoft, and HE0238 SEDs. We also calculate the ionic column densities of excited and ground states of N iii to estimate the electron number density and location of the outflow using the Chianti atomic database. Results. The MF87, UVsoft, and HE0238 SEDs yield nitrogen and sulfur abundances at super-solar, solar, and sub-solar values, respectively, with a spread of 0.4 to 3 times solar. Additionally, we determined an electron number density of log(ne) greater than 3.3 cm-3, with the outflow possibly extending up to a maximum distance of 2.8 kpc. Conclusions. Our results indicate solar metallicity within a 60 percent uncertainty range, driven by variations in the chosen SED and photoionization models. This study underscores the importance of SEDs impact on determining chemical abundances in quasars outflows. These findings highlight the necessity of considering a wider range of possible abundances, spanning from sub solar to super solar values.
- [45] arXiv:2411.14235 [pdf, html, other]
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Title: A study of the star clusters' population in the giant molecular cloud G174+2.5T.A. Permyakova (UrFU), G. Carraro (UniPD), A.F. Seleznev (UrFU), A.M. Sobolev (UrFU), D.A. Ladeyschikov (UrFU), M.S. Kirsanova (Inasan)Comments: 30 pages, 16 figures, accepted for publication in the Astronomical JournalSubjects: Astrophysics of Galaxies (astro-ph.GA)
We study the structure, interstellar absorption, color-magnitude diagrams, kinematics, and dynamical state of embedded star clusters in the star-forming region associated with the giant molecular cloud G174+2.5. Our investigation is based on photometric data from the UKIDSS Galactic Plane Survey catalog and astrometric data from the Gaia DR3 catalogs. First, we recover all the known embedded clusters and candidate clusters in the region using surface density maps. Then, for the detected clusters, we determine their general parameters: the center positions, radii, number of stars, and reddening. To evaluate the reddening, we use both the NICEST algorithm and the Q-method. Both methods produce consistent extinction maps in the regions of the four studied clusters. However, the Q-method yields a much smaller color scatter in the CMD. For four clusters in particular (S235~North-West, S235~A-B-C, S235~Central, and S235~East1+East2), we were able to compute individual membership probabilities, the cluster distances, the cluster masses, and their average proper motions. By building on these results, we have studied the clusters' kinematics and dynamics. Moreover, we estimate the mass of the gas component and the star formation efficiency (SFE) in the regions of these four clusters. Finally, we provide an estimate of the total energy of the stellar and gas components in the area of these four clusters to determine whether the clusters are bound (here we consider a `cluster' as the system `stars + gas'). The gravitational bound strongly depends on the region for which we estimate the gas mass. If we consider the mass of the entire cloud, all these four clusters turn out to be bound.
- [46] arXiv:2411.14241 [pdf, html, other]
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Title: Observing planetary gaps in the gas of debris disksComments: 18 pages, 14 figures, Accepted in A&ASubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Recent ALMA observations discovered consequent amounts (i.e., up to a few $10^{-1}\; \rm M_\oplus$) of CO gas in debris disks that were expected to be gas-free. This gas is in general estimated to be mostly composed of CO, C, and O (i.e., $\rm H_2$-poor), unlike the gas present in protoplanetary disks ($\rm H_2$-rich). At this stage, the majority of planet formation already occurred, and giant planets might be evolving in these disks. While planets have been directly observed in debris disks (e.g., $\beta$ Pictoris), their direct observations are challenging due to the weak luminosity of the planets. In this paper, with the help of hydrodynamical simulations (with FARGO3D) coupled with a radiative transfer code (RADMC-3D) and an observing tool (CASA), we show that planet-gas interactions can produce observable substructures in this late debris disk stage. While it is tricky to observe gaps in the CO emission of protoplanetary disks, the unique properties of the gaseous debris disks allow us to observe planetary gaps in the gas. Depending on the total mass of the gaseous debris disk, kinks can also be observed. We derive a simple criterion to estimate in which conditions gaps would be observable and apply it to the known gaseous debris disk surrounding HD138813. In our framework, we find that planets as small as $0.5 \; \rm M_J$ can produce observable gaps and investigate under which conditions (i.e., gas and planets characteristics) the substructure become observable with ALMA. The first observations of planet-gas interactions in debris disks can lead to a new way to indirectly detect exoplanets, reaching a population that could not be probed before, such as giant planets that are too cold to be detected by direct imaging.
- [47] arXiv:2411.14253 [pdf, html, other]
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Title: Revisiting the BE99 method for the study of outflowing gas in protostellar jetsComments: 12 pages, 10 figures, accepted to A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA)
An established method measuring the hydrogen ionisation fraction in shock excited gas is the BE99 method, which utilises six bright forbidden emission lines of [SII]6716, 6731, [NII]6548, 6583, and [OI]6300, 6363. We aim to extent the BE99 method by including more emission lines in the blue and near-infrared part of the spectrum ($\lambda$ = 3500-11000A), and considering higher hydrogen ionisation fractions ($x_e > 0.3$). In addition, we investigate how a non-equilibrium state of the gas and the presence of extinction influence the BE99 technique. We find that plenty additional emission line ratios can in principle be exploited as extended curves (or stripes) in the ($x_e, T_e$)-diagram. If the BE99 equilibrium is reached and extinction is corrected for, all stripes overlap in one location in the ($x_e, T_e$)-diagram indicating the existing gas parameters. The application to the Par Lup 3-4 outflow shows that the classical BE99 lines together with the [NI]5198+5200 lines do not meet in one locationin the ($x_e, T_e$)-diagram. This indicates that the gas parameters derived from the classical BE99 method are not fully consistent with other observed line ratios. A multi-line approach is necessary to determine the gas parameters. From our analysis we derive $n_e \sim$ 45 000 cm^-3 - 53000 cm^-3 , $T_e$ = 7600K - 8000K, and $x_e \sim$ 0.027 - 0.036 for the Par Lup 3-4 outflow. For the 244-440 Proplyd we were able to use the line ratios of [SII]6716+6731, [OI]6300+6363, and [OII]7320, 7330 in the BE99 diagram to estimate the ionisation fraction at knot E3 ($x_e = 0.58 \pm 0.05$). In conclusion, exploiting new line ratios reveals more insights on the state of the gas. Our analysis indicates, however, that a multi-line approach is more robust in deriving gas parameters, especially for high density gas.
- [48] arXiv:2411.14270 [pdf, html, other]
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Title: Y Gem, a Symbiotic Star Outshined by its Asymptotic Giant Branch Primary ComponentComments: 13 pages, 9 Figures, 4 Tables; Accepted to A&ASubjects: Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE)
A considerable number of asymptotic giant branch (AGB) stars exhibit UV excess and/or X-ray emission indicative of the presence of a binary companion. AGB stars are so bright that they easily outshine their companions, making almost impossible their identification. Y Gem has been known to be a far-UV- and X-ray-bright AGB star for some decades now, but the nature of its companion, whether it is a main-sequence star or a white dwarf (WD) in a symbiotic system (SySt), is disputed. Our goal is to uncover the true nature of Y Gem to help us peer into the possible misidentified population of SySts. Multi-wavelength IR, optical, UV and X-ray observations have been analyzed to investigate the properties of the stellar components and accretion process in Y Gem. In particular, an optical spectrum of Y Gem is presented here for the first time, while X-ray data are interpreted by means of reflection models produced by an accretion disk and material in its vicinity. The optical spectrum exhibits the typical saw-shaped features of molecular absorptions in addition to narrow recombination and forbidden emission lines. The presence of the emission lines and the analysis of the extinction-corrected UV spectrum suggest a hot component with $T_\mathrm{eff}\approx$60,000 K, $L$=140 L$_{\odot}$, and $R$=0.11 R$_{\odot}$, very likely an accreting WD. The late component is found to be an 1.1 M$_\odot$ AGB star with $T_\mathrm{eff}$=3350 K and $R$=240 R$_\odot$. Using IR, optical, UV, and X-ray data, we found that Y Gem is a S-type SySt whose compact component is accreting at an estimated mass accretion rate of $\dot{M}_\mathrm{acc}=2.3\times10^{-7}$ M$_\odot$ yr$^{-1}$. At such accretion rate, the accreting WD has reached the stable and steady burning phase where no recurrent events are expected.
- [49] arXiv:2411.14271 [pdf, html, other]
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Title: The properties of the interstellar medium in dusty, star-forming galaxies at $z \sim 2-4$: The shape of the CO spectral line energy distributionsDominic J. Taylor (Durham University-CEA), A. M. Swinbank (Durham University-CEA), Ian Smail, Annagrazia Puglisi, Jack E. Birkin, Ugne Dudzeviciute, Chian-Chou Chen, S. Ikarashi, Marta Frias Castillo, Axel Weiss, Zefeng Li, Scott C. Chapman, Jasper Jansen, E. F. Jimenez-Andrade, Leah K. Morabito (Durham University-CEA), Eric J. Murphy, Matus Rybak, P. P. van der WerfComments: Accepted for publication in MNRAS; 17 pages, 7 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The molecular gas in the interstellar medium (ISM) of star-forming galaxy populations exhibits diverse physical properties. We investigate the $^{12}$CO excitation of twelve dusty, luminous star-forming galaxies at $z \sim 2-4$ by combining observations of the $^{12}$CO from $J_{\rm up} = 1$ to $J_{\rm up} = 8$. The spectral line energy distribution (SLED) has a similar shape to NGC 253, M82, and local ULIRGs, with much stronger excitation than the Milky Way inner disc. By combining with resolved dust continuum sizes from high-resolution $870$-$\mu$m ALMA observations and dust mass measurements determined from multi-wavelength SED fitting, we measure the relationship between the $^{12}$CO SLED and probable physical drivers of excitation: star-formation efficiency, the average intensity of the radiation field $\langle U\rangle$, and the star-formation rate surface density. The primary driver of high-$J_{\rm up}$ $^{12}$CO excitation in star-forming galaxies is star-formation rate surface density. We use the ratio of the CO($3-2$) and CO($6-5$) line fluxes to infer the CO excitation in each source and find that the average ratios for our sample are elevated compared to observations of low-redshift, less actively star-forming galaxies and agree well with predictions from numerical models that relate the ISM excitation to the star-formation rate surface density. The significant scatter in the line ratios of a factor $\approx 3$ within our sample likely reflects intrinsic variations in the ISM properties which may be caused by other effects on the excitation of the molecular gas, such as cosmic ray ionization rates and mechanical heating through turbulence dissipation.
- [50] arXiv:2411.14273 [pdf, html, other]
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Title: Examining the evolution of the Supersoft X-ray Source RX J$0513.9-6951$Comments: 11 pages, 10 figures, 4 tables, submitted to A&ASubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Supersoft X-ray sources (SSS) are thought to be accreting white dwarfs (WDs) in close binary systems, with thermonuclear burning on their surfaces. The SSS RX J$0513.9-6951$ in the Large Magellanic Cloud (LMC) exhibits cyclic variations between optical low and high states, which are anti-correlated with its X-ray flux. This behaviour is believed to result from the periodic expansion and contraction of the WD due to variations in the accretion rate in the system. We analyse eight high-resolution XMM and six grating Chandra spectra of RX J$0513.9-6951$ with our grid of model atmosphere spectra of hot WDs computed under the assumption of local thermodynamic equilibrium. Our aim is to test a contraction model of the source variability by tracking the evolution of the WD properties. The used grid of hot WD model atmospheres spans a wide range of effective temperatures ($T_{\rm eff}=100-1000\,\rm kK$ in steps of $25\,\rm kK$) and eight values of surface gravity $\log g$. The LMC chemical composition was assumed. The obtained fitting parameters ($T_{\rm eff}$, $\log g$, and bolometric luminosity $L$) evolve on the $T_{\rm eff}- \log g$ and $T_{\rm eff}- L$ planes. This evolution follows the model tracks of WDs with masses of $1.05-1.15\,M_{\odot}$ and thermonuclear burning on the surface. The analysis has showed that the optical brightness of the system is lower when the WD is larger, more luminous, and more effectively illuminates the accretion disc. These results contradict the contraction model, which predicts the opposite behaviour of the source. We use a model, that assumes that the far UV/soft X-ray flux is reprocessed into the optical band due to multiple scattering in the cloud system above the accretion disc. More significant illumination can lead to rarefying of the cloud slab, thereby reducing the reprocessing efficiency and making the source fainter in the optical band.
- [51] arXiv:2411.14310 [pdf, html, other]
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Title: Bird's-eye View of Molecular Gas across Stephan's Quintet Galaxy Group and Intra-group MediumB. H. C. Emonts (1), P. N. Appleton (2), U. Lisenfeld (3), P. Guillard (4), C. K. Xu (5), W. T. Reach (6), L. Barcos-Munoz (1), A. Labiano (8), P. M. Ogle (9), E. O'Sullivan (10), A. Togi (11), S. C. Gallagher (12), P. Aromal (12), P.-A. Duc (13), K. Alatalo (9), F. Boulanger (14), T. Diaz-Santos (15), G. Helou (16) ((1) NRAO, (2) Caltech/IPAC, (3) Univ. Granada, (4) IAP, (5) NAOC, (6) SSI, (7) ESA, (9) STScI, (10) CfA, (11) TXST, (12) Western Univ., (13) ObAS, (14) UPMC, (15) FORTH, (16) IPAC)Comments: Accepted for publication in ApJSubjects: Astrophysics of Galaxies (astro-ph.GA)
We present the large-scale distribution and kinematics of cold molecular gas across the compact galaxy group Stephan's Quintet, based on CO(2-1) observations performed with the Atacama Compact Array (ACA) and CO(1-0) data from the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We find coherent structures of molecular gas associated with the galaxies and intra-group medium, which follow the distribution of warm H$_{2}$ previously seen with the James Webb Space Telescope (JWST). CO is associated with a ridge of shocked gas that crosses the galaxy group, and with a spiral arm of the intruding galaxy NGC7318b, which interacts with the intra-group medium along the ridge. Although the ridge contains widespread shocks, turbulent gas, and warm H$_{2}$, the CO lines are narrower than elsewhere in Stephan's Quintet (FWHM~25-65 km/s), indicative of settled cold gas. At a distinctly different velocity, CO is found in the active galaxy NGC7319 and Northern star-forming region SQ-A. A bridge of turbulent molecular gas connects NGC7319 with the ridge, covering a gap of ~700 km/s between these structures. The gas excitation ranges from $L'_{\rm CO(2-1)}$/$L'_{\rm CO(1-0)}$ ~ 0.3 in the bridge and SQ-A, to ~0.5 along the ridge, to near unity in the center of NGC7319. We also detect either a molecular outflow or turbulent molecular gas associated with the radio source in NGC7319. These ACA data are part of a program with the Atacama Large Millimeter/submillimeter Array (ALMA) and JWST to study molecular gas physics from the largest to the smallest scales across the intra-group medium of Stephan's Quintet.
- [52] arXiv:2411.14327 [pdf, html, other]
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Title: The MUSE Extremely Deep Field: Classifying the Spectral Shapes of Lya Emitting GalaxiesE. Vitte, A. Verhamme, P. Hibon, F. Leclercq, B. Alcalde Pampliega, J. Kerutt, H. Kusakabe, J. Matthee, Y. Guo, R. Bacon, M. Maseda, J. Richard, J. Pharo, J. Schaye, L. Boogaard, T. Nanayakkara, T. ContiniComments: 36 pages, 29 figures, 9 tables, accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA)
The Hydrogen Lyman-alpha (Lya) line shows a large variety of shapes which is caused by factors at different scales, from the interstellar medium to the intergalactic medium. This work aims to provide a systematic inventory and classification of the spectral shapes of Lya emission lines to understand the general population of high-redshift Lya emitting galaxies (LAEs). Using the data from the MUSE eXtremely Deep Field, we select 477 galaxies at z=2.8-6.6. We develop a method to classify Lya emission lines in four spectral and three spatial categories, by combining a spectral analysis with a narrow-band image analysis. We measure spectral properties, such as the peak separation and the blue-to-total flux ratio. To ensure a robust sample for statistical analysis, we define a final unbiased sample of 206 galaxies by applying thresholds for signal-to-noise ratio, peak separation, and Lya luminosity. Our analysis reveals that between 32% and 51% of the galaxies exhibit double-peaked profiles. This fraction seems to evolve dependently with the Lya luminosity, while we don't notice a severe decrease of this fraction with redshift. A large amount of these double-peaked profiles shows blue-dominated spectra, suggesting unique gas dynamics and inflow characteristics in some high-redshift galaxies. Among the double-peaked galaxies, 4% are spurious detections. Around 20% out of the 477 sources of the parent sample lie in a complex environment, meaning there are other clumps or galaxies at the same redshift within a distance of 30kpc. Our results suggest that the Lya double-peak fraction may trace the evolution of IGM attenuation, but faintest galaxies are needed to be observed at high redshift. In addition, it is crucial to obtain secure systemic redshifts for LAEs to better constrain the nature of the double-peaks.
- [53] arXiv:2411.14338 [pdf, html, other]
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Title: On the Morphology of Relativistically Broadened Line Emission from Axisymmetric Equatorial Accretion DisksComments: 27 pages, 11 figuresSubjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
Single-frequency emission from an accretion disk around a black hole is broadened into a line profile due to gravitational redshift and the motion of the disk's particles relative to the observer. The ensemble of relativistically broadened emission frequencies from the disk elements forms the spectrum viewed by an observer. Over the past decades, the broadened spectra of accreting systems have been used to constrain the spin of the black hole, the observer's inclination, and the astrophysical model parameters of the system. These inferences are usually made under the assumption that the accretion disk consists of particles orbiting around the black hole on stable circular orbits in the equatorial plane. Under this Standard disk model, in this work, we revisit line profile morphology, i.e., its extent, kinks, and fall-off. We provide a unified analytical explanation for these line profile morphological features, which encode the black hole spin, viewing inclination, and locations of the disk's inner and outer edges. We then show that these features, however, are model-dependent, by parametrically relaxing some of the astrophysical assumptions. In particular, we explore how allowing the disk particles to deviate from stable circular orbits rapidly degenerates the characteristic features of the line profile under the Standard disk model. Our results further demonstrate how sensitive our understanding of black hole and system properties can be to assumptions we make when interpreting these types of measurements.
- [54] arXiv:2411.14377 [pdf, html, other]
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Title: The constraining power of the Marked Power Spectrum: an analytical studyMarco Marinucci, Gabriel Jung, Michele Liguori, Andrea Ravenni, Francesco Spezzati, Adam Andrews, Marco Baldi, William R. Coulton, Dionysios Karagiannis, Francisco Villaescusa-Navarro, Benjamin WandletComments: 18 pages, 7 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The marked power spectrum - a two-point correlation function of a transformed density field - has emerged as a promising tool for extracting cosmological information from the large-scale structure of the Universe. In this work, we present the first comprehensive analytical study of the marked power spectrum's sensitivity to primordial non-Gaussianity (PNG) of the non-local type. We extend previous effective field theory frameworks to incorporate PNG, developing a complete theoretical model that we validate against the Quijote simulation suite. Through a systematic Fisher analysis, we compare the constraining power of the marked power spectrum against traditional approaches combining the power spectrum and bispectrum (P+B). We explore different choices of mark parameters to evaluate their impact on parameter constraints, particularly focusing on equilateral and orthogonal PNG as well as neutrino masses. Our analysis shows that while marking up underdense regions yields optimal constraints in the low shot-noise regime, the marked power spectrum's performance for discrete tracers with BOSS-like number densities does not surpass that of P+B analysis at mildly non-linear scales ($k \lesssim 0.25 \,h/\text{Mpc}$). However, the marked approach offers several practical advantages, including simpler estimation procedures and potentially more manageable systematic effects. Our theoretical framework reveals how the marked power spectrum incorporates higher-order correlation information through terms resembling tree-level bispectra and power spectrum convolutions. This work establishes a robust foundation for applying marked statistics to future large-volume surveys.
- [55] arXiv:2411.14383 [pdf, html, other]
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Title: Not Just a Dot: the complex UV morphology and underlying properties of Little Red DotsP. Rinaldi, N. Bonaventura, G. H. Rieke, S. Alberts, K. I. Caputi, W. M. Baker, S. Baum, R. Bhatawdekar, A. J. Bunker, S. Carniani, E. Curtis-Lake, F. D'Eugenio, E. Egami, Z. Ji, K. Hainline, J. M. Helton, X. Lin, J. Lyu, B. D. Johnson, Z. Ma, R. Maiolino, P. G. Pérez-González, M. Rieke, B. E. Robertson, I. Shivaei, M. Stone, Y. Sun, S. Tacchella, H. Übler, C. C. Williams, C. N. A. Willmer, C. Willott, J. Zhang, Y. ZhuComments: 28 pages, 9 figures, 3 tables. Submitted to ApJ. Comments are welcome!Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We analyze 99 photometrically selected Little Red Dots (LRDs) at z ~ 4-8 in the GOODS fields, leveraging ultra-deep JADES NIRCam short-wavelength (SW) data. We examine the morphology of 30 LRDs; the remaining 69 are predominantly compact, i.e. are strongly dominated by sources < 400 pc in diameter and lack extended components even in stacked SW band images. Among the LRDs selected for morphological analysis, 50% show at least two distinct, associated sources or galaxy components, while the others appear as single sources with highly asymmetric structures. We find median stellar masses of log10(M*/Msun) = 9.07(-0.08)(+0.11) for pure stellar models with Av ~ 1.16(+0.11)(-0.21) mag, and log10(M*/Msun) = 9.67(+0.17)(-0.27) for models including AGNs, where Av ~ 2.74(+0.55)(-0.71) mag, consistent with recent results showing LRDs tend to have high stellar masses and dust content when fitted with AGN models. NIRSpec spectra are available for 15 sources, 6 of which fall within the morphological analysis sample and show multiple components. Among these 15, broad H-alpha emission is detected in 40%, with full-width half-maximum (FWHM) ranging from 1200 to 2900 km/s. One source exhibits broad H-beta emission with FWHM = 2000 +/- 500 km/s. Analysis of line ratios probing the interstellar medium (ISM) reveals a composite nature, indicating AGN activity combined with stellar processes. These findings suggest LRDs have a mixed nature, with AGN signatures in some cases linked to disturbed morphologies observed at rest-frame UV wavelengths.
- [56] arXiv:2411.14392 [pdf, html, other]
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Title: Convolutional Vision Transformer for Cosmology Parameter InferenceComments: Accepted at the NeurIPS ML4PS Workshop 2024. The code is available at this https URLSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Parameter inference is a crucial task in modern cosmology that requires accurate and fast computational methods to handle the high precision and volume of observational datasets. In this study, we explore a hybrid vision transformer, the Convolution vision Transformer (CvT), which combines the benefits of vision transformers and convolutional neural networks. We use this approach to infer the $\Omega_m$ and $\sigma_8$ cosmological parameters from simulated dark matter and halo fields. Our experiments indicate that the constraints on $\Omega_m$ and $\sigma_8$ obtained using CvT are better than the traditional vision transformer (ViT) and CNN, using either dark matter or halo fields. For CvT, pretraining on dark matter fields proves advantageous for improving constraints using halo fields compared to training a model from the beginning. However, ViT and CNN do not show these benefits. The CvT is more efficient than ViT since, despite having more parameters, it requires a training time similar to that of ViT and has similar inference times. The code is available at \url{this https URL}.
- [57] arXiv:2411.14395 [pdf, html, other]
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Title: Cooling of neutron stars in soft X-ray transients with realistic crust compositionComments: 10 pages, 7 figures, JHEAP, acceptedSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Thermal radiation of neutron stars in soft X-ray transients (SXTs) in a quiescent state is believed to be powered by the heat deposited in the stellar crust due to nuclear reactions during accretion. Confronting observations of this radiation with simulations helps to verify theoretical models of the dense matter in neutron stars. We simulate the thermal evolution of the SXTs with theoretical models of the equation of state and composition of the accreted crust. The new family of such models were recently developed within a thermodynamically consistent approach by modeling the nuclear evolution of an accreted matter as it sinks toward the stellar center, starting from representative thermonuclear ash compositions. The crust cooling curves computed with the traditional and modern theory are compared with observations of SXTs MXB 1659-29 and IGR J17480-2446. We show that the new and traditional models of the accreted neutron star crusts are similar in their capability to explain the thermal evolution of neutron stars in SXTs. Both kinds of models require inclusion of additional ingredients not supplied by the current theory, such as the shallow heating and variation of thermal conductivity, to fit observations.
- [58] arXiv:2411.14419 [pdf, html, other]
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Title: Combining summary statistics with simulation-based inference for the 21 cm signal from the Epoch of ReionizationComments: 11 pages, submitted to A&ASubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The 21 cm signal from the Epoch of Reionization will be observed with the up-coming Square Kilometer Array (SKA). SKA should yield a full tomography of the signal which opens the possibility to explore its non-Gaussian properties. How can we extract the maximum information from the tomography and derive the tightest constraint on the signal? In this work, instead of looking for the most informative summary statistics, we investigate how to combine the information from two sets of summary statistics using simulation-based inference. To this purpose, we train Neural Density Estimators (NDE) to fit the implicit likelihood of our model, the LICORICE code, using the Loreli II database. We train three different NDEs: one to perform Bayesian inference on the power spectrum, one to do it on the linear moments of the Pixel Distribution Function (PDF) and one to work with the combination of the two. We perform $\sim 900$ inferences at different points in our parameter space and use them to assess both the validity of our posteriors with Simulation-based Calibration (SBC) and the typical gain obtained by combining summary statistics. We find that our posteriors are biased by no more than $\sim 20 \%$ of their standard deviation and under-confident by no more than $\sim 15 \%$. Then, we establish that combining summary statistics produces a contraction of the 4-D volume of the posterior (derived from the generalized variance) in 91.5 % of our cases, and in 70 to 80 % of the cases for the marginalized 1-D posteriors. The median volume variation is a contraction of a factor of a few for the 4D posteriors and a contraction of 20 to 30 % in the case of the marginalized 1D posteriors. This shows that our approach is a possible alternative to looking for sufficient statistics in the theoretical sense.
New submissions (showing 58 of 58 entries)
- [59] arXiv:2401.02413 (cross-list from stat.ML) [pdf, html, other]
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Title: Simulation-Based Inference with Quantile RegressionComments: 9+13 pages, 8+8 figures, ICML 2024Subjects: Machine Learning (stat.ML); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Instrumentation and Methods for Astrophysics (astro-ph.IM); Machine Learning (cs.LG)
We present Neural Quantile Estimation (NQE), a novel Simulation-Based Inference (SBI) method based on conditional quantile regression. NQE autoregressively learns individual one dimensional quantiles for each posterior dimension, conditioned on the data and previous posterior dimensions. Posterior samples are obtained by interpolating the predicted quantiles using monotonic cubic Hermite spline, with specific treatment for the tail behavior and multi-modal distributions. We introduce an alternative definition for the Bayesian credible region using the local Cumulative Density Function (CDF), offering substantially faster evaluation than the traditional Highest Posterior Density Region (HPDR). In case of limited simulation budget and/or known model misspecification, a post-processing calibration step can be integrated into NQE to ensure the unbiasedness of the posterior estimation with negligible additional computational cost. We demonstrate that NQE achieves state-of-the-art performance on a variety of benchmark problems.
- [60] arXiv:2411.13621 (cross-list from physics.hist-ph) [pdf, html, other]
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Title: Underestimation of Hubble constant error bars: a historical analysisComments: 9 pages, accepted to be published in the conference proceedings of the session "Current Status of the H_0 and growth tensions: theoretical models and model-independent constraints" within 17th Marcel Grossmann Meeting (Pescara, Italy, July 7th-12th 2024). arXiv admin note: substantial text overlap with arXiv:2210.07078Subjects: History and Philosophy of Physics (physics.hist-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
An analysis of a historical compilation of Hubble-Lemaître constant values ($H_0$: 163 data points measured between 1976 and 2019) assuming the standard cosmological model gives a $\chi^2$ value of the dispersion with respect to the weighted average of 580, much larger than the number of points, which has an associated probability that is very low. This means that Hubble tensions were always present in the literature, due either to the underestimation of statistical error bars associated with the observed parameter measurements, or to the fact that systematic errors were not properly taken into account in many of the measurements.
The fact that the underestimation of error bars for $H_0$ is so common might explain the apparent 4.4-sigma discrepancy by Riess et al. As a matter of fact, more recent precise $H_0$ measurements with JWST data by Freedman et al. using standard candles in galaxies find there is no tension with CMBR data, possibly indicating that previously Riess et al. had underestimated their errors.
Here we have carried out a recalibration of the probabilities. The tension of 4.4-$\sigma $, estimated between the local Cepheid-supernova distance ladder and cosmic microwave background (CMB) data, is indeed a 2.1-$\sigma $ tension in equivalent terms of a normal distribution, with an associated probability $P$ = 0.036 (1 in 28). This can be increased to an equivalent tension of 2.5-$\sigma $ in the worst cases of claimed 6-$\sigma $ tension, which may in any case happen as a random statistical fluctuation.
If Hubble tensions were always present in the literature, and present day tensions are not more important than previous ones, why, then, is there so much noise and commotion surrounding Hubble tension after 2019? It is suggested here that this obeys a sociological phenomenon of ``groupthink''. - [61] arXiv:2411.13625 (cross-list from cond-mat.stat-mech) [pdf, other]
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Title: Partition function approach to non-Gaussian likelihoods: information theory and state variables for Bayesian inferenceRebecca Maria Kuntz, Heinrich von Campe, Tobias Röspel, Maximilian Philipp Herzog, Björn Malte SchäferSubjects: Statistical Mechanics (cond-mat.stat-mech); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The significance of statistical physics concepts such as entropy extends far beyond classical thermodynamics. We interpret the similarity between partitions in statistical mechanics and partitions in Bayesian inference as an articulation of a result by Jaynes (1957), who clarified that thermodynamics is in essence a theory of information. In this, every sampling process has a mechanical analogue. Consequently, the divide between ensembles of samplers in parameter space and sampling from a mechanical system in thermodynamic equilibrium would be artificial. Based on this realisation, we construct a continuous modelling of a Bayes update akin to a transition between thermodynamic ensembles. This leads to an information theoretic interpretation of Jazinsky's equality, relating the expenditure of work to the influence of data via the likelihood. We propose one way to transfer the vocabulary and the formalism of thermodynamics (energy, work, heat) and statistical mechanics (partition functions) to statistical inference, starting from Bayes' law. Different kinds of inference processes are discussed and relative entropies are shown to follow from suitably constructed partitions as an analytical formulation of sampling processes. Lastly, we propose an effective dimension as a measure of system complexity. A numerical example from cosmology is put forward to illustrate these results.
- [62] arXiv:2411.13634 (cross-list from hep-ph) [pdf, html, other]
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Title: Individual Neutrino Masses From a SupernovaComments: 18 pages, 13 figures, 2 tables. Comments welcome!Subjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
A nearby supernova will carry an unprecedented wealth of information about astrophysics, nuclear physics, and particle physics. Because supernova are fundamentally neutrino driven phenomenon, our knowledge about neutrinos -- particles that remain quite elusive -- will increase dramatically with such a detection. One of the biggest open questions in particle physics is related to the masses of neutrinos. Here we show how a galactic supernova provides information about the masses of each of the three mass eigenstates \emph{individually}, at some precision, and is well probed at JUNO. This information comes from several effects including time delay and the physics within the supernova. The time delay feature is strongest during a sharp change in the flux such as the neutronization burst; additional information may also come from a QCD phase transition in the supernova or if the supernova forms a black hole. We consider both standard cases as dictated by local oscillation experiments as well as new physics motivated scenarios where neutrino masses may differ across the galaxy.
- [63] arXiv:2411.13636 (cross-list from hep-th) [pdf, html, other]
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Title: Cosmological Correlators at the Loop LevelComments: 47 pagesSubjects: High Energy Physics - Theory (hep-th); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Phenomenology (hep-ph)
Cosmological correlators encode rich information about physics at the Hubble scale and may exhibit characteristic oscillatory signals due to the exchange of massive particles. Although many 1-loop processes, especially those that break de Sitter (dS) boosts, can generate significant leading signals for various particle models in cosmological collider physics, the precise results for these correlators or their full signals remain unknown due to the lack of symmetry. In this work, we apply the method of partial Mellin-Barnes (PMB) representation to the calculation of cosmological correlators at the loop level. As a first step, we use the PMB representation to calculate four-point cosmological correlators with bubble topology. We find that both the nonlocal and local signals arise from the factorized part, validating the cutting rules proposed in previous work, and are free from UV divergence. Furthermore, the UV divergence originates solely from the background piece and can be manifestly canceled by introducing the appropriate counterterm, similar to the procedure in flat spacetime. We also demonstrate how to renormalize the 1-loop correlators in Mellin space. After a consistency check with known results for the covariant case, we provide new analytical results for the signals generated from a nontrivial dS-boost-breaking bubble.
- [64] arXiv:2411.13641 (cross-list from hep-ph) [pdf, html, other]
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Title: Bounds on the bubble wall velocityComments: 47 pages, 8 figuresSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Determining the bubble wall velocity in first-order phase transitions is a challenging task, requiring the solution of (coupled) equations of motion for the scalar field and Boltzmann equations for the particles in the plasma. The collision terms appearing in the Boltzmann equation present a prominent source of uncertainty as they are often known only at leading log accuracy. In this paper, we derive upper and lower bounds on the wall velocity, corresponding to the local thermal equilibrium and ballistic limits. These bounds are completely independent of the collision terms.
For the ballistic approximation, we argue that the inhomogeneous plasma temperature and velocity distributions across the bubble wall should be taken into account. This way, the hydrodynamic obstruction previously observed in local thermal equilibrium is also present for the ballistic approximation. This is essential for the ballistic approximation to provide a lower bound on the wall velocity. We use a model-independent approach to study the behaviour of the limiting wall velocities as a function of a few generic parameters, and we test our developments in the singlet extended Standard Model. - [65] arXiv:2411.13714 (cross-list from gr-qc) [pdf, other]
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Title: Gravitational-wave signatures of non-violent non-localityComments: 10 pages, 9 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
Measurement of gravitational waves can give precision tests of the nature of black holes and compact objects. In this work, we test Giddings' non-violent non-locality proposal, which posits that quantum information is transferred via a nonlocal interaction that generates metric perturbations around black holes. In contrast to firewalls, these quantum fluctuations would be spread out over a larger distance range up to a Schwarzschild radius away. In this letter, we model the modification to the gravitational waveform from non-violent non-locality. We modify the nonspinning EOBNRv2 effective one body waveform to include metric perturbations that are due to a random Gaussian process. We find that the waveform exhibits random deviations which are particularly important in the late inspiral-plunge phase. We find an optimal dephasing parameter for detecting this effect with a principal component analysis. This is particularly intriguing because it predicts random phase deviations across different gravitational wave events, providing theoretical support for hierarchical tests of general relativity. We estimate the constraint on the perturbations in non-violent non-locality with events for the LIGO-Virgo network and for a third generation network.
- [66] arXiv:2411.13801 (cross-list from gr-qc) [pdf, html, other]
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Title: Unique and Universal Effects of Oscillation in Eccentric Orbital Binary Black Hole Mergers beyond Orbital AveragingComments: 6 pages, 5 figures, submittedSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE)
We analyze 192 sets of binary black hole merger data in eccentric orbits obtained from RIT, decomposing the radiation energy into three distinct phases through time: inspiral, late inspiral to merger, and ringdown. Our investigation reveals a universal oscillatory behavior in radiation energy across these phases, influenced by varying initial eccentricities. From a post-Newtonian perspective, we compare the orbital average of radiation energy with the non-orbital average during the inspiral phase. Our findings indicate that the oscillatory patterns arise from non-orbital average effects, which disappear when orbital averaging is applied. This orbital effect significantly impacts the mass, spin, and recoil velocity of the merger remnant, with its influence increasing as the initial eccentricity rises. Specifically, in the post-Newtonian framework, the amplitudes of oscillations for mass, spin, and recoil velocity at ${e_t}_0 = 0.5$ (initial temporal eccentricity of PN) are enhanced by approximately 10, 5, and 7 times, respectively, compared to those at ${e_t}_0 = 0.1$. For a circular orbit, where ${e_t}_0 = 0.0$, the oscillations vanish entirely. These findings have important implications for waveform modeling, numerical relativity simulations, and the characterization of binary black hole formation channels.
- [67] arXiv:2411.13871 (cross-list from gr-qc) [pdf, html, other]
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Title: Charged Fuzzy Dark Matter Black HolesComments: 19 pages, 9 figuresJournal-ref: Physics of the Dark Universe 46, 101727 (2024)Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We investigate the impact of fuzzy dark matter (FDM) on supermassive black holes (SMBHs) characterized by a spherical charge distribution. This work introduces a new class of spherically symmetric, self-gravitational relativistic charged models for FDM haloes, using the Einasto density model. This study enables the dark matter (DM) to appear as the matter ingredient, which constructs the black hole and extends the non-commutative mini black hole stellar solutions. By considering the charged anisotropic energy-momentum tensor with an equation of state (EoS) $p_{r}=-\rho$, we explore various black hole solutions for different values of the Einasto index and mass parameter. Our approach suggests that the central density of the resulting black hole model mimics the usual de Sitter core. Furthermore, we discuss the possibility of constructing a charged self-gravitational droplet by replacing the above-mentioned EoS with a non-local one. However, under these circumstances, the radial pressure is observed to be negative. Ultimately, we consider various possibilities of constructing DM black holes, featuring intermediate masses that could evolve into galaxies. Consequently, some of these theoretical models have the potential to replace the usual black hole solutions of the galactic core. Simultaneously, these models are physically beneficial for being comprised of the fundamental matter component of the cosmos. Due to the outcomes of this paper, we would be able to study the connection between BH and DM by formulating stable stellar structures featuring fuzzy mass distributions derived from the Einasto distribution of DM halos.
- [68] arXiv:2411.13915 (cross-list from hep-ex) [pdf, html, other]
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Title: An accurate solar axions ray-tracing response of BabyIAXOS. Ahyoune, K. Altenmueller, I. Antolin, S. Basso, P. Brun, F. R. Candon, J. F. Castel, S. Cebrian, D. Chouhan, R. Della Ceca, M. Cervera-Cortes, V. Chernov, M. M. Civitani, C. Cogollos, E. Costa, V. Cotroneo, T. Dafni, A. Derbin, K. Desch, M. C. Diaz-Martin, A. Diaz-Morcillo, D. Diez-Ibanez, C. Diez Pardos, M. Dinter, B. Doebrich, I. Drachnev, A. Dudarev, A. Ezquerro, S. Fabiani, E. Ferrer-Ribas, F. Finelli, I. Fleck, J. Galan, G. Galanti, M. Galaverni, J. A. Garcia, J. M. Garcia-Barcelo, L. Gastaldo, M. Giannotti, A. Giganon, C. Goblin, N. Goyal, Y. Gu, L. Hagge, L. Helary, D. Hengstler, D. Heuchel, S. Hoof, R. Iglesias-Marzoa, F. J. Iguaz, C. Iniguez, I. G. Irastorza, K. Jakovcic, D. Kaefer, J. Kaminski, S. Karstensen, M. Law, A. Lindner, M. Loidl, C. Loiseau, G. Lopez-Alegre, A. Lozano-Guerrero, B. Lubsandorzhiev, G. Luzon, I. Manthos, C. Margalejo, A. Marin-Franch, J. Marques, F. Marutzky, C. Menneglier, M. Mentink, S. Mertens, J. Miralda-Escude, H. Mirallas, F. Muleri, V. Muratova, J. R. Navarro-Madrid, X. F. Navick, K. Nikolopoulos, A. Notari, A. Nozik, L. Obis, A. Ortiz-de-Solorzano, T. O'Shea, J. von Oy, G. Pareschi, T. Papaevangelou, K. Perez, O. Perez, E. Picatoste, M. J. Pivovaroff, J. Porron, M. J. Puyuelo, A. Quintana, J. Redondo, D. Reuther, A. Ringwald, M. Rodrigues, A. Rubini, S. Rueda-TeruelComments: 36 pages, 18 figures, 4 tables, Submitted to JHEPSubjects: High Energy Physics - Experiment (hep-ex); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR); Computational Physics (physics.comp-ph); Data Analysis, Statistics and Probability (physics.data-an)
BabyIAXO is the intermediate stage of the International Axion Observatory (IAXO) to be hosted at DESY. Its primary goal is the detection of solar axions following the axion helioscope technique. Axions are converted into photons in a large magnet that is pointing to the sun. The resulting X-rays are focused by appropriate X-ray optics and detected by sensitive low-background detectors placed at the focal spot. The aim of this article is to provide an accurate quantitative description of the different components (such as the magnet, optics, and X-ray detectors) involved in the detection of axions. Our efforts have focused on developing robust and integrated software tools to model these helioscope components, enabling future assessments of modifications or upgrades to any part of the IAXO axion helioscope and evaluating the potential impact on the experiment's sensitivity. In this manuscript, we demonstrate the application of these tools by presenting a precise signal calculation and response analysis of BabyIAXO's sensitivity to the axion-photon coupling. Though focusing on the Primakoff solar flux component, our virtual helioscope model can be used to test different production mechanisms, allowing for direct comparisons within a unified framework.
- [69] arXiv:2411.13978 (cross-list from cs.RO) [pdf, html, other]
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Title: Breadboarding the European Moon Rover System: discussion and results of the analogue field test campaignCristina Luna, Augusto Gómez Eguíluz, Jorge Barrientos-Díez, Almudena Moreno, Alba Guerra, Manuel Esquer, Marina L. Seoane, Steven Kay, Angus Cameron, Carmen Camañes, Philipp Haas, Vassilios Papantoniou, Armin Wedler, Bernhard Rebele, Jennifer Reynolds, Markus LandgrafComments: 6 pages, 5 figures, conference International Conference on Space RoboticsJournal-ref: 2024 International Conference on Space Robotics (iSpaRo), Luxembourg, Luxembourg, 2024, pp. 145-150Subjects: Robotics (cs.RO); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
This document compiles results obtained from the test campaign of the European Moon Rover System (EMRS) project. The test campaign, conducted at the Planetary Exploration Lab of DLR in Wessling, aimed to understand the scope of the EMRS breadboard design, its strengths, and the benefits of the modular design. The discussion of test results is based on rover traversal analyses, robustness assessments, wheel deflection analyses, and the overall transportation cost of the rover. This not only enables the comparison of locomotion modes on lunar regolith but also facilitates critical decision-making in the design of future lunar missions.
- [70] arXiv:2411.14018 (cross-list from gr-qc) [pdf, html, other]
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Title: Dissecting Buchdahl's limit: A surgeon's guide to compact objectsComments: 37 pages, 7 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Theory (hep-th)
One of the theoretical motivations behind the belief that black holes as described by general relativity exist in nature is that it is hard to find matter configurations that mimic their properties, especially their compactness. One of the classic results that goes in this direction is the so-called Buchdahl limit: a bound for the maximum compactness that, under a few assumptions, static fluid spheres in hydrostatic equilibrium can possibly have. We highlight two of the main assumptions that could be violated in physically realistic situations: i) isotropy and ii) an outward-decreasing monotonicity of the density profile, which, as we discuss in detail, can be understood as a form of energy condition. We construct a pair of toy models that exemplify how the Buchdahl limit can be overcome if any of these two assumptions is individually relaxed. In particular, we show that relaxing the monotonicity assumption alone yields a new, less restrictive compactness limit as long as the energy density is not allowed to become negative. If negative energies are permitted, the compactness of these toy models can be as close to the black hole limit as desired. We also discuss how these toy models represent some of the main features of realistic systems, and how they could be extended to find more refined models.
- [71] arXiv:2411.14063 (cross-list from gr-qc) [pdf, html, other]
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Title: Probing dark matter halo profiles with multi-band observations of gravitational wavesComments: 13 pages, 5 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Astrophysics of Galaxies (astro-ph.GA); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
In this paper, we evaluate the potential of multiband gravitational wave observations to constrain the properties of static dark matter spikes around intermediate-mass ratio inspirals. The influence of dark matter on the orbital evolution of the compact binary is incorporated as a correction to the inspiral Newtonian gravitational waveform. We show that the observations from the proposed space-based detector GWSat, sensitive within the deci-Hz frequency band, when combined with that of the third-generation ground-based detectors like the Einstein Telescope and Cosmic Explorer, will produce significantly improved error estimates for all parameters. In particular, our results demonstrate that the joint multiband approach substantially refines the bounds on the dark matter spike parameters-namely, the power-law index and spike density-by factors of approximately $10^6$ and $10^3$, respectively, compared to observations employing only third-generation gravitational wave detectors.
- [72] arXiv:2411.14091 (cross-list from hep-ph) [pdf, html, other]
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Title: Towards a precision calculation of $N_{\rm eff}$ in the Standard Model IV: Impact of positronium formationComments: 16 pages, 2 figures, 2 tablesSubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present in this work the first assessment of the previously unexplored effect of positronium formation on the value of the effective number of neutrino species in the Standard Model, $N_{\mathrm{eff}}^{\mathrm{SM}}$. We find that the expected impact on $N_{\mathrm{eff}}^{\mathrm{SM}}$ crucially depends on the temperature at which positronium equilibrates as well as the rate at which this equilibration happens. The dominant factor limiting the formation process is the melting of positronium at high temperatures driven by Debye screening of the electrostatic potential and scatterings with real photons. Using simple physical arguments, we estimate that positronium forms at temperatures around $50-80$ keV. If formation and equilibration were instantaneous, the resulting change in $N_{\mathrm{eff}}^{\mathrm{SM}}$ would be at most $|\Delta N_{\mathrm{eff}}| \sim 10^{-4}$, comparable to other uncertainties in the current benchmark value for $N_{\mathrm{eff}}^{\mathrm{SM}}$. A more gradual formation could however yield a larger change, necessitating in turn a more detailed investigation before we can conclusively neglect the effect of positronium formation on $N_{\mathrm{eff}}^{\mathrm{SM}}$.
- [73] arXiv:2411.14223 (cross-list from gr-qc) [pdf, html, other]
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Title: Gravitational wave signatures from reheating in Chern-Simons running-vacuum cosmologyCharalampos Tzerefos, Theodoros Papanikolaou, Spyros Basilakos, Emmanuel N. Saridakis, Nick E. MavromatosComments: 17 pages without appendices (18 in total), 4 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
Within the context of a Chern-Simons running-vacuum-model (RVM) cosmology, one expects an early-matter dominated (eMD) reheating period after RVM inflation driven by the axion field. Treating thus in this work Chern-Simons RVM cosmology as an effective $f(R)$ gravity theory characterized by logarithmic corrections of the spacetime curvature, we study the gravitational-wave (GW) signal induced by the nearly-scale invariant inflationary adiabatic curvature perturbations during the transition from the eMD era driven by the axion to the late radiation-dominated era. Remarkably, by accounting for the extra GW scalaron polarization present within $f(R)$ gravity theories, we find regions in the parameter space of the theory where one is met with a distinctive induced GW signal with a universal $f^6$ high-frequency scaling compared to the $f^7$ scaling present in general relativity (GR). Interestingly enough, for axion masses $m_a$ higher than 1 GeV and axion gauge couplings $f_a$ above $10^{-3}$ Planck mass, one can produce induced GW spectra within the sensitivity bands of future GW observatories such as the Einstein Telescope (ET), the Laser Interferometer Space Antenna (LISA), the Big Bang Observer (BBO) and the Square Kilometer Arrays (SKA).
- [74] arXiv:2411.14380 (cross-list from gr-qc) [pdf, html, other]
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Title: Modified gravity from Weyl connection and the $f(R,\cal{A})$ extensionComments: 10 pages, 2 figuresSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We use Weyl connection and Weyl geometry in order to construct novel modified gravitational theories. In the simplest case where one uses only the Weyl-connection Ricci scalar as a Lagrangian, the theory recovers general relativity. However, by upgrading the Weyl field to a dynamical field with a general potential and/or general couplings constructed from its trace, leads to new modified gravity theories, where the extra degree of freedom is the Weyl field. Additionally, since the Weyl-connection Ricci scalar differs from the Levi-Civita Ricci scalar by terms up to first derivatives of the Weyl field, the resulting field equations for both the metric and the Weyl field are of second order, and thus the theory is free from Ostrogradsky ghosts. Finally, we construct the most general theory, namely the $f(\tilde{R},\cal{A})$ gravity, which is also ghost free and has $2+2$ degrees of freedom. Applying the above classes of theories at a cosmological framework we obtain an effective dark energy sector of geometrical origin. In the simplest class of theories we are able to obtain an effective cosmological constant, and thus we recover $\Lambda$CDM paradigm, nevertheless in more general cases we acquire a dynamical dark energy. These theories can reproduce the thermal history of the Universe, and the corresponding dark energy equation-of-state parameter presents a rich behavior.
- [75] arXiv:2411.14399 (cross-list from math.NA) [pdf, html, other]
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Title: DiscoTEX 1.0: Discontinuous collocation and implicit-turned-explicit (IMTEX) integration symplectic, symmetric numerical algorithms with high order jumps for differential equations II: extension to higher-orders of numerical convergenceComments: 15 pages, 5 figures, 2 tables. Second paper of a series of papers. See this http URL:2401.08758 for application of these algorithms to numerical black hole perturbation theory. Comments welcomed. arXiv admin note: text overlap with arXiv:2401.08758Subjects: Numerical Analysis (math.NA); Instrumentation and Methods for Astrophysics (astro-ph.IM); General Relativity and Quantum Cosmology (gr-qc); Mathematical Physics (math-ph)
\texttt{DiscoTEX} is a highly accurate numerical algorithm for computing numerical weak-form solutions to distributionally sourced partial differential equations (PDE)s. The aim of this second paper, succeeding \cite{da2024discotex}, is to present its extension up to twelve orders. This will be demonstrated by computing numerical weak-form solutions to the distributionally sourced wave equation and comparing it to its exact solutions. The full details of the numerical scheme at higher orders will be presented.
Cross submissions (showing 17 of 17 entries)
- [76] arXiv:2208.02265 (replaced) [pdf, html, other]
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Title: The distribution and morphologies of Fornax Cluster dwarf galaxies suggest they lack dark matterComments: 35 pages, 24 figures, 4 tables, 7.5 MB. Accepted for publication in Monthly Notices of the Royal Astronomical Society in this form, first figure caption and equation 65 fixed, references updatedJournal-ref: Monthly Notices of the Royal Astronomical Society, volume 515, issue 2, pages 2981-3013 (2022)Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
Due to their low surface brightness, dwarf galaxies are particularly susceptible to tidal forces. The expected degree of disturbance depends on the assumed gravity law and whether they have a dominant dark halo. This makes dwarf galaxies useful for testing different gravity models. In this project, we use the Fornax Deep Survey (FDS) dwarf galaxy catalogue to compare the properties of dwarf galaxies in the Fornax Cluster with those predicted by the Lambda cold dark matter ($\Lambda$CDM) standard model of cosmology and Milgromian dynamics (MOND). We construct a test particle simulation of the Fornax system. We then use the MCMC method to fit this to the FDS distribution of tidal susceptibility $\eta$ (half-mass radius divided by theoretical tidal radius), the fraction of dwarfs that visually appear disturbed as a function of $\eta$, and the distribution of projected separation from the cluster centre. This allows us to constrain the $\eta$ value at which dwarfs should get destroyed by tides. Accounting for an $r'$-band surface brightness limit of 27.8 magnitudes per square arcsec, the required stability threshold is $\eta_{\textrm{destr}} = 0.25^{+0.07}_{-0.03}$ in $\Lambda$CDM and $ 1.88^{+0.85}_{-0.53}$ in MOND. The $\Lambda$CDM value is in tension with previous $\textit{N}$-body dwarf galaxy simulations, which indicate that $\eta_{\textrm{destr}} \approx 1$. Our MOND $\textit{N}$-body simulations indicate that $\eta_{\textrm{destr}} = 1.70 \pm 0.30$, which agrees well with our MCMC analysis of the FDS. We therefore conclude that the observed deformations of dwarf galaxies in the Fornax Cluster and the lack of low surface brightness dwarfs towards its centre are incompatible with $\Lambda$CDM expectations but well consistent with MOND.
- [77] arXiv:2307.05689 (replaced) [pdf, html, other]
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Title: Magnetar emergence in a peculiar gamma-ray burst from a compact star mergerH. Sun, C.-W. Wang, J. Yang, B.-B. Zhang, S.-L. Xiong, Y.-H. I. Yin, Y. Liu, Y. Li, W.-C. Xue, Z. Yan, C. Zhang, W.-J. Tan, H.-W. Pan, J.-C. Liu, H.-Q. Cheng, Y.-Q. Zhang, J.-W. Hu, C. Zheng, Z.-H. An, C. Cai, Z.-M. Cai, L. Hu, C. Jin, D.-Y. Li, X.-Q. Li, H.-Y. Liu, M. Liu, W.-X. Peng, L.-M. Song, S.-L. Sun, X.-J. Sun, X.-L. Wang, X.-Y. Wen, S. Xiao, S.-X. Yi, F. Zhang, W.-D. Zhang, X.-F. Zhang, Y.-H. Zhang, D.-H. Zhao, S.-J. Zheng, Z.-X. Ling, S.-N. Zhang, W. Yuan, B. ZhangComments: 54 pages, 11 figures, 5 tables, accepted for publication in National Science ReviewSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
The central engine that powers gamma-ray bursts (GRBs), the most powerful explosions in the universe, is still not identified. Besides hyper-accreting black holes, rapidly spinning and highly magnetized neutron stars, known as millisecond magnetars, have been suggested to power both long and short GRBs. The presence of a magnetar engine following compact star mergers is of particular interest as it would provide essential constraints on the poorly understood equation of state for neutron stars. Indirect indications of a magnetar engine in these merger sources have been observed in the form of plateau features present in the X-ray afterglow light curves of some short GRBs. Additionally, some X-ray transients lacking gamma-ray bursts (GRB-less) have been identified as potential magnetar candidates originating from compact star mergers. Nevertheless, smoking gun evidence is still lacking for a magnetar engine in short GRBs, and the associated theoretical challenges have been raised. Here we present a comprehensive analysis of the broad-band prompt emission data of a peculiar, very bright GRB 230307A. Despite its apparently long duration, the prompt emission and host galaxy properties are consistent with a compact star merger origin, as suggested by its association with a kilonova. Intriguingly, an extended X-ray emission component shows up as the $\gamma$-ray emission dies out, signifying the likely emergence of a magnetar central engine. We also identify an achromatic temporal break in the high-energy band during the prompt emission phase, which was never observed in previous bursts and reveals a narrow jet with half opening angle of approximately $\sim 3.4^\circ (R_{GRB}/10^{15}~{cm})^{-1/2}$, where $R_{GRB}$ is the GRB prompt emission radius.
- [78] arXiv:2307.12092 (replaced) [pdf, html, other]
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Title: Binary vision: The merging black hole binary mass distribution via iterative density estimationComments: 14 pages, 12 figures, Equivalent to published versionJournal-ref: Astrophysical Journal, 2024, Volume 960, Issue 1, Article 65Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
Binary black hole (BBH) systems detected via gravitational-wave (GW) emission are a recently opened astrophysical frontier with many unknowns and uncertainties. Accurate reconstruction of the binary distribution with as few assumptions as possible is desirable for inference on formation channels and environments. Most population analyses have, though, assumed a power law in binary mass ratio $q$, and/or assumed a universal $q$ distribution regardless of primary mass. Kernel density estimation (KDE)-based methods allow us to dispense with such assumptions and directly estimate the joint binary mass distribution. We deploy a self-consistent iterative method to estimate this full BBH mass distribution, finding local maxima in primary mass consistent with previous investigations and a secondary mass distribution with a partly independent structure, inconsistent with both power laws and with a constant function of $q$. We find a weaker preference for near-equal mass binaries than in most previous investigations; instead, the secondary mass has its own "spectral lines" at slightly lower values than the primary, and we observe an anti-correlation between primary and secondary masses around the ~$10M_\odot$ peak.
- [79] arXiv:2310.16304 (replaced) [pdf, html, other]
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Title: Deep Learning Approach to Photometric Redshift EstimationComments: Final Submission File to IEEE XploreSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
Data-driven approaches play a crucial role in space computing, and our paper focuses on analyzing data to learn more about celestial objects. Photometric redshift, a measure of the shift of light towards the red part of the spectrum, helps determine the distance of celestial objects. This study used a dataset from the Sloan Digital Sky Survey (SDSS) with five magnitudes alongside their corresponding redshift labels. Traditionally, redshift prediction relied on spectral distribution templates (SEDs), which, though effective, are costly and limited, especially for large datasets. This paper explores data-driven methodologies instead of SEDs. By employing a decision tree regressor and a fully connected neural network (FCN), we found that the FCN outperforms the decision tree regressor in RMS. The results show that data-driven estimation is a valuable tool for astronomical surveys. With the adaptability to complement previous methods, FCNs will reshape the field of redshift estimation.
- [80] arXiv:2311.04146 (replaced) [pdf, html, other]
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Title: Galaxy Spectra neural Network (GaSNet). II. Using Deep Learning for Spectral Classification and Redshift PredictionsFucheng Zhong, Nicola R. Napolitano, Caroline Heneka, Rui Li, Franz Erik Bauer, Nicolas Bouche, Johan Comparat, Young-Lo Kim, Jens-Kristian Krogager, Marcella Longhetti, Jonathan Loveday, Boudewijn F. Roukema, Benedict L. Rouse, Mara Salvato, Crescenzo Tortora, Roberto J. Assef, Letizia P. Cassarà, Luca Costantin, Scott Croom, Luke J M Davies, Alexander Fritz, Guillaume Guiglion, Andrew Humphrey, Emanuela Pompei, Claudio Ricci, Cristóbal Sifón, Elmo Tempel, Tayyaba ZafarComments: 23 pages and 31 figures. The published version of MNRASSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Astrophysics of Galaxies (astro-ph.GA)
Large sky spectroscopic surveys have reached the scale of photometric surveys in terms of sample sizes and data complexity. These huge datasets require efficient, accurate, and flexible automated tools for data analysis and science exploitation. We present the Galaxy Spectra Network/GaSNet-II, a supervised multi-network deep learning tool for spectra classification and redshift prediction. GaSNet-II can be trained to identify a customized number of classes and optimize the redshift predictions for classified objects in each of them. It also provides redshift errors, using a network-of-networks that reproduces a Monte Carlo test on each spectrum, by randomizing their weight initialization. As a demonstration of the capability of the deep learning pipeline, we use 260k Sloan Digital Sky Survey spectra from Data Release 16, separated into 13 classes including 140k galactic, and 120k extragalactic objects. GaSNet-II achieves 92.4% average classification accuracy over the 13 classes (larger than 90% for the majority of them), and an average redshift error of approximately 0.23% for galaxies and 2.1% for quasars. We further train/test the same pipeline to classify spectra and predict redshifts for a sample of 200k 4MOST mock spectra and 21k publicly released DESI spectra. On 4MOST mock data, we reach 93.4% accuracy in 10-class classification and an average redshift error of 0.55% for galaxies and 0.3% for active galactic nuclei. On DESI data, we reach 96% accuracy in (star/galaxy/quasar only) classification and an average redshift error of 2.8% for galaxies and 4.8% for quasars, despite the small sample size available. GaSNet-II can process ~40k spectra in less than one minute, on a normal Desktop GPU. This makes the pipeline particularly suitable for real-time analyses of Stage-IV survey observations and an ideal tool for feedback loops aimed at night-by-night survey strategy optimization.
- [81] arXiv:2312.09440 (replaced) [pdf, html, other]
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Title: Model-independent Gamma-Ray Bursts Constraints on Cosmological Models Using Machine LearningComments: 24 pages, 5 tables, 8 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
In this paper, we calibrate the luminosity relation of gamma-ray bursts (GRBs) with the machine learning (ML) algorithms from the Pantheon+ sample of type Ia supernovae in a cosmology-independent way. By using K-Nearest Neighbors (KNN) and Random Forest (RF) selected with the best performance in the ML algorithms, we calibrate the Amati relation (\unboldmath{$E_{\rm p}$-$E_{\rm iso}$}) relation with the A219 sample to construct the Hubble diagram of GRBs. Via the Markov Chain Monte Carlo numerical method with GRBs at high redshift and latest observational Hubble data, we find the results of constraints on cosmological models by using KNN and RF algorithms are consistent with those obtained from GRBs calibrated by using the Gaussian Process.
- [82] arXiv:2401.13046 (replaced) [pdf, html, other]
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Title: TEMPLATES: Direct Abundance Constraints for Two Lensed Lyman-Break GalaxiesBrian Welch, Grace M. Olivier, Taylor A. Hutchison, Jane R. Rigby, Danielle A. Berg, Manuel Aravena, Matthew B. Bayliss, Jack E. Birkin, Scott C. Chapman, Håkon Dahle, Gourav Khullar, Keunho J. Kim, Guillaume Mahler, Matthew A. Malkan, Desika Narayanan, Kedar A. Phadke, Keren Sharon, J.D.T. Smith, Manuel Solimano, Justin S. Spilker, Joaquin D. Viera, David VizganComments: Accepted to the Astrophysical Journal's Focus Issue on the TEMPLATES JWST Early Release Science Program. 16 pages, 6 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA)
Using integrated spectra for two gravitationally lensed galaxies from the JWST TEMPLATES Early Release Science program, we analyze faint auroral lines, which provide direct measurements of the gas-phase chemical abundance. For the brighter galaxy, SGAS1723$+$34 ($z = 1.3293$), we detect the [OIII]$\lambda4363$, [SIII]$\lambda6312$, and [OII]$\lambda\lambda$7320,7330 auroral emission lines, and set an upper limit for the [NII]$\lambda5755$ line. For the second galaxy, SGAS1226$+$21 ($z = 2.925$), we do not detect any auroral lines, and report upper limits. With these measurements and upper limits, we constrain the electron temperatures in different ionization zones within both of these galaxies. For SGAS1723$+$34, where auroral lines are detected, we calculate direct oxygen and nitrogen abundances, finding an N/O ratio consistent with observations of nearby ($z\sim 0$) galaxies. These observations highlight the potent combination of JWST and gravitational lensing to measure faint emission lines in individual distant galaxies and to directly study the chemical abundance patterns in those galaxies.
- [83] arXiv:2402.18645 (replaced) [pdf, html, other]
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Title: The conceptual design of the 50-meter Atacama Large Aperture Submillimeter Telescope (AtLAST)Tony Mroczkowski, Patricio A. Gallardo, Martin Timpe, Aleksej Kiselev, Manuel Groh, Hans Kaercher, Matthias Reichert, Claudia Cicone, Roberto Puddu, Pierre Dubois-dit-Bonclaude, Daniel Bok, Erik Dahl, Mike Macintosh, Simon Dicker, Isabelle Viole, Sabrina Sartori, Guillermo Andrés Valenzuela Venegas, Marianne Zeyringer, Michael Niemack, Sergio Poppi, Rodrigo Olguin, Evanthia Hatziminaoglou, Carlos De Breuck, Pamela Klaassen, Francisco Miguel Montenegro-Montes, Thomas ZimmererComments: This version addresses the second round A&A referee reportsSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
The submillimeter and millimeter ((sub-)mm) sky contains a vast wealth of information that is both complementary and inaccessible to other wavelengths. Over half the light we receive is observable at (sub-)mm wavelengths, yet we have mapped only a small portion of the sky at sufficient spatial resolution and sensitivity to detect and resolve distant galaxies or star forming cores within their large-scale environments. For decades the astronomical community has highlighted the need for a large, high-throughput (sub-)mm ($\lambda\sim 0.35-10$ mm) single dish. The Atacama Large Aperture Submillimeter Telescope (AtLAST), with its 50-m aperture and $2^\circ$ maximal field of view, aims to be such a facility. We present here the preliminary design concept for AtLAST, developed through an EU Horizon 2020-funded design study. Our design approach begins with a long lineage of (sub-)mm telescopes, relies on calculations and simulations to realize the optics, and uses finite element analysis to optimize the designs for the mechanical structure and subsystems. The demanding technical requirements for AtLAST, set by transformative science goals, have motivated the design effort to combine novel concepts with lessons learned from the past experience of previous efforts. The result is an innovative rocking chair design with six instrument bays, two of which are mounted on Nasmyth platforms, inside a large receiver cabin. Ultimately, AtLAST aims to achieve a surface accuracy of $\leq 20~\mu$m root mean square half wavefront error, corresponding a Ruze efficiency $>50\%$ at 950~GHz. We conclude that closed-loop metrology of the active primary surface will likely be required to achieve our surface accuracy goal. In the next phase of the project, we will prototype and test such metrology on existing platforms, with a goal of delivering a mature, construction-ready design by the end of this decade.
- [84] arXiv:2404.18714 (replaced) [pdf, html, other]
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Title: Black hole-neutron star mergers with massive neutron stars in numerical relativityComments: 19 pages, 14 figuresJournal-ref: Phys. Rev. D 110, 063016 (2024)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc)
We study the merger of black hole-neutron star (BH-NS) binaries in numerical relativity, focusing on the properties of the remnant disk and the ejecta, varying the mass of compactness of the NS and the mass and spin of the BH. We find that within the precision of our numerical simulations, the remnant disk mass and ejecta mass normalized by the NS baryon mass ($\hat{M}_{\rm{rem}}$ and $\hat{M}_{\rm{eje}}$, respectively), and the cutoff frequency $f_{\rm{cut}}$ normalized by the initial total gravitational mass of the system at infinite separation approximately agree among the models with the same NS compactness $C_{\rm{NS}}=M_{\rm{NS}}/R_{\rm{NS}}$, mass ratio $Q=M_{\rm{BH}}/M_{\rm{NS}}$, and dimensionless BH spin $\chi_{\rm{BH}}$ irrespective of the NS mass $M_{\rm{NS}}$ in the range of $1.092$--$1.691\,M_\odot$. This result shows that the merger outcome depends sensitively on $Q$, $\chi_{\rm BH}$, and $C_{\rm{NS}}$ but only weekly on $M_{\rm{NS}}$. This justifies the approach of studying the dependence of NS tidal disruptions on the NS compactness by fixing the NS mass but changing the EOS. We further perform simulations with massive NSs of $M_{\rm{NS}}=1.8M_{\odot}$, and compare our results of $\hat{M}_{\rm{rem}}$ and $\hat{M}_{\rm{eje}}$ with those given by existing fitting formulas to test their robustness for more compact NSs. We find that the fitting formulas obtained in the previous studies are accurate within the numerical errors assumed, while our results also suggest that further improvement is possible by systematically performing more precise numerical simulations.
- [85] arXiv:2405.00095 (replaced) [pdf, html, other]
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Title: Assessing the accuracy of the star formation rate measurements by direct star count in molecular cloudsSami Dib, Jian Wen Zhou, Sébastien Comerón, Luis E. Garduño, Valery V. Kravtsov, Paul C. Clark, Guang-Xing Li, Maritza A. Lara-López, Tie Liu, Mohsen Shadmehri, James R. DoughtyComments: Accepted for publication in Astronomy & AstrophysicsSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
Star formation estimates based on the counting of YSOs is commonly applied to nearby star-forming regions in the Galaxy. With this method, the SFRs are measured using the counts of YSOs in a particular protostellar Class, a typical protostellar mass, and the lifetime associated with this Class. However, the assumptions underlying the validity of the method such as that of a constant star formation history (SFH) and whether the method is valid for all protostellar Classes has never been fully tested. In this work, we use Monte Carlo models to test the validity of the method. We build synthetic clusters in which stars form at times that are randomly drawn from a specified SFH. The latter is either constant or time-dependent with a burst like behavior. The masses of the protostars are randomly drawn from an IMF which can be either similar to that of the Milky Way field or be variable . For each star in every cluster, the lifetimes associated with the different protostellar classes are also randomly drawn from Gaussian distribution functions centered around their most likely value as suggested by the observations. We find that only the SFR derived using the Class 0 population can reproduce the true SFR at all epochs, and this is true irrespective of the shape of the SFH. For a constant SFH, the SFR derived using the more evolved populations of protostars (Classes I, F, II, and III) reproduce the real SFR only at later epochs which correspond to epochs at which their numbers have reached a steady state. For a time-dependent burst-like SFH, all SFR estimates based on the number counts of the evolved populations fail to reproduce the true SFR. We also show how the offsets between Class I and Class II based SFRs and the true SFR plotted as a function of the number ratios of Class I and Class II versus Class III YSOs can be used in order to constrain the SFH of observed molecular clouds.
- [86] arXiv:2405.09633 (replaced) [pdf, html, other]
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Title: Cross-correlating IceCube neutrinos with a large set of galaxy samples around redshift z ~ 1Comments: 17 pages, 10 figures. Matches version accepted by PRD, significantly expanded section IIIB to clarify modeling of beamJournal-ref: Phys. Rev. D 110 (2024), 103025Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The IceCube neutrino telescope has detected a diffuse flux of high-energy astrophysical neutrinos, but the sources of this flux have largely remained elusive. Using the 10-year IceCube public dataset, we search for correlations between neutrino events and tracers of large-scale structure (LSS). We conduct a combined cross-correlation analysis using several wide-area galaxy catalogs spanning a redshift range of z = 0.1 to z ~ 2.5 as well as maps of the cosmic infrared background. We do not detect a definitive signal, but find tantalizing hints of a potential positive correlation between neutrinos and the tracers of LSS. We additionally construct a simple model to interpret galaxy-neutrino cross-correlations in terms of the redshift distribution of neutrino sources. We put upper limits on the clustering amplitude of neutrinos based on the measured cross-correlations with galaxies and forecast the improvements on these constraints that can be obtained using future detectors. We show that, in the future, neutrino-galaxy cross-correlations should be a powerful probe to constrain properties of neutrino source populations.
- [87] arXiv:2405.11285 (replaced) [pdf, html, other]
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Title: CO Observations of the Type Ia Supernova Remnant 3C 397 by the Nobeyama 45-m Radio Telescope: Possible Evidence for the Single-Degenerated ExplosionDaisuke Ito, Hidetoshi Sano, Kazuhiro Nakazawa, Ikuyuki Mitsuishi, Yasuo Fukui, Hiroshi Sudou, Hiroshi TakabaComments: 11 pages, 9 figures, accepted for publication in The Astrophysical Journal (ApJ)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA)
We present a new CO observation toward the Type Ia supernova remnant (SNR) 3C 397 using the Nobeyama 45-m radio telescope at an unprecedent angular resolution of $\sim$18''. We newly found that the CO cloud at $V_{\mathrm{LSR}}$ = 55.7-62.2 km s$^{-1}$ (60 km s$^{-1}$ cloud) shows a good spatial correspondence with the radio continuum shell. We also found an expanding gas motion of the 60 km s$^{-1}$ cloud with an expansion velocity of $\sim$3 km s$^{-1}$, which is thought to be formed by the pre-and/or post-supernova feedback. By considering the positions of Galactic spiral arms and the X-ray/HI absorption studies, we concluded that 3C 397 is physically associated with the 60 km s$^{-1}$ cloud rather than the previously known CO cloud at $V_{\mathrm{LSR}}$ $\sim$30 km s$^{-1}$. Given that the previously measured pre-shock density is $\sim$2-5 cm$^{-3}$, the expanding motion of the 60 km s$^{-1}$ cloud was likely formed by the pre-supernova feedback known as optically thick wind. The scenario is consistent with that 3C 397 exploded inside a wind-blown bubble as a single degenerate system.
- [88] arXiv:2406.08012 (replaced) [pdf, html, other]
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Title: Interaction of an outflow with surrounding gaseous clouds as the origin of the late-time radio flares in TDEsComments: 14 pages, 15 figures. Submitted to ApJ. A new version with some modificationsSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Close encounter between a star and a supermassive black hole (SMBH) results in the tidal disruption of the star, known as a tidal disruption event (TDE). Recently, a few TDEs, e.g., ASASSN-15oi and AT2018hyz, have shown late-time (hundreds of days after their UV/optical peaks) radio flares with radio luminosities of $10^{38\sim39}$ erg/s. The super-Eddington fallback or accretion in a TDE may generate a mass outflow. Here we investigate a scenario that the late-time radio flares come from the interaction of the outflow with the circum-nuclear gaseous clouds, in addition to the slow-evolving emission component due to the outflow-diffuse medium interaction. We calculate the associated radio temporal and spectral signatures and find that they reproduce well the observations. The outflows have the inferred velocity of 0.2$c\sim0.6$$c$, the total mass of $10^{-3}\sim10^{-1}$ $\mathrm{M_{\odot}}$ and the ejection duration of a month to a year. The distances of the clouds to the SMBH are $0.1\sim1$ pc. This scenario has advantages in explaining the long delay, sharpness of the rise and the multiplicity of the late radio flares. Future observations may build up a much larger sample of late-time radio flares and enable their use as a probe of the TDE physics and the host circumnuclear environment.
- [89] arXiv:2406.10338 (replaced) [pdf, html, other]
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Title: Bursty Star Formation in Dwarfs is Sensitive to Numerical Choices in Supernova Feedback ModelsEric Zhang, Laura V. Sales, Federico Marinacci, Paul Torrey, Mark Vogelsberger, Volker Springel, Hui Li, Rüdiger Pakmor, Thales A. GutckeComments: Published ApJ; 18 pages, 12 figures; comments welcomeJournal-ref: ApJ 975 229 (2024)Subjects: Astrophysics of Galaxies (astro-ph.GA); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE)
Simulations of galaxy formation are mostly unable to resolve the energy-conserving phase of individual supernova events, having to resort to subgrid models to distribute the energy and momentum resulting from stellar feedback. However, the properties of these simulated galaxies, including the morphology, stellar mass formed and the burstiness of the star formation history, are highly sensitive to numerical choices adopted in these subgrid models. Using the {\small SMUGGLE} stellar feedback model, we compute idealized simulations of a $M_{\rm vir} \sim 10^{10} \, \msun$ dwarf galaxy, a regime where most simulation codes predict significant burstiness in star formation, resulting in strong gas flows that lead to the formation of dark matter cores. We find that by varying only the directional distribution of momentum imparted from supernovae to the surrounding gas, while holding the total momentum per supernova constant, bursty star formation may be amplified or completely suppressed, and the total stellar mass formed can vary by as much as a factor of $\sim 3$. In particular, when momentum is primarily directed perpendicular to the gas disk, less bursty and lower overall star formation rates result, yielding less gas turbulence, more disky morphologies and a retention of cuspy dark matter density profiles. An improved understanding of the non-linear coupling of stellar feedback into inhomogeneous gaseous media is thus needed to make robust predictions for stellar morphologies and dark matter core formation in dwarfs independent of uncertain numerical choices in the baryonic treatment.
- [90] arXiv:2406.16898 (replaced) [pdf, html, other]
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Title: Detecting kHz gravitons from a neutron star merger with a multi-mode resonant mass detectorComments: 8 + 3 pages, 2 FiguresSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Theory (hep-th); Instrumentation and Detectors (physics.ins-det); Quantum Physics (quant-ph)
We propose a multi-mode bar consisting of mass elements of decreasing size for the implementation of a gravitational version of the photo-electric effect through the stimulated absorption of up to kHz gravitons from a binary neutron star merger and post-merger. We find that the multi-mode detector has normal modes that retain the coupling strength to the gravitational wave of the largest mass-element, while only having an effective mass comparable to the mass of the smallest element. This allows the normal modes to have graviton absorption rates due to the tonne-scale largest mass, while the single graviton absorption process in the normal mode could be resolved through energy measurements of a mass-element in-principle smaller than pico-gram scale. We argue the feasibility of directly counting gravito-phonons in the bar through energy measurements of the end mass. This improves the transduction of the single-graviton signal, enhancing the feasibility of detecting single gravitons.
- [91] arXiv:2407.21371 (replaced) [pdf, html, other]
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Title: Einstein Probe discovery of EP J005245.1-722843: a rare BeWD binary in the Small Magellanic Cloud?A. Marino, H. Yang, F. Coti Zelati, N. Rea, S. Guillot, G. K. Jaisawal, C. Maitra, J.-U. Ness, F. Haberl, E. Kuulkers, W. Yuan, H. Feng, L. Tao, C. Jin, H. Sun, W. Zhang, W. Chen, E. P. J. van den Heuvel, R. Soria, B. Zhang, S.-S. Weng, L. Ji, G. B. Zhang, X. Pan, Z. Lv, C. Zhang, Z. Ling, Y. Chen, S. Jia, Y. Liu, H. Q. Cheng, D. Y. Li, K. C. Gendreau, M. Ng, T. E. StrohmayerComments: 9 pages, 5 figures; accepted for publication in ApJLSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
On May 27 2024, the Wide-field X-ray Telescope onboard the Einstein Probe (EP) mission detected enhanced X-ray emission from a new transient source in the Small Magellanic Cloud (SMC) during its commissioning phase. Prompt follow-up with the EP Follow-up X-ray Telescope, the Swift X-ray Telescope and NICER have revealed a very soft, thermally emitting source (kT$\sim$0.1 keV at the outburst peak) with an X-ray luminosity of $L\sim4\times10^{38}$ erg s$^{-1}$, labelled EP J005245.1-722843. This super-soft outburst faded very quickly in a week time. Several emission lines and absorption edges were present in the X-ray spectrum, including deep Nitrogen (0.67 keV) and Oxygen (0.87 keV) absorption edges. The X-ray emission resembles the SSS phase of typical nova outbursts from an accreting white dwarf (WD) in a binary system, despite the X-ray source being historically associated with an O9-B0e massive star exhibiting a 17.55 days periodicity in the optical band. The discovery of this super-soft outburst suggests that EP J005245.1-722843 is a BeWD X-ray binary: an elusive evolutionary stage where two main-sequence massive stars have undergone a common envelope phase and experienced at least two episodes of mass transfer. In addition, the very short duration of the outburst and the presence of Ne features hint at a rather massive, i.e., close to the Chandrasekhar limit, Ne-O WD in the system.
- [92] arXiv:2408.13465 (replaced) [pdf, html, other]
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Title: New Insights into Type-I Solar Noise Storms from High Angular Resolution Spectroscopic Imaging with the Upgraded Giant Metrewave Radio TelescopeComments: Published at the Astrophysical Journal, 14 pages, 10 figuresJournal-ref: ApJ 975 122(2024)Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Type-I solar noise storms are perhaps the most commonly observed active radio emissions from the Sun at meter-wavelengths. Noise storms have a long-lived and wideband continuum background with superposed islands of much brighter narrowband and short-lived emissions, known as type-I bursts. There is a serious paucity of studies focusing on the morphology of these two types of emissions, primarily because of the belief that coronal scattering will always wash out any features at small angular scales. However, it is important to investigate their spatial structures in detail to make a spatio-temporal connection with observations at extreme-ultraviolet/ X-ray bands to understand the detailed nature of these emissions. In this work, we use high angular resolution observations from the upgraded Giant Metrewave Radio Telescope to demonstrate that it is possible to detect structures with angular scales as small as $\sim 9\arcsec$, about three times smaller than the smallest structure reported to date from noise storms. Our observations also suggest while the individual type-I bursts are narrowband in nature, the bursts are probably caused by traveling disturbance(s) inducing magnetic reconnections at different coronal heights, and thus leading to correlated change in the morphology of the type-I bursts observed at a wide range of frequencies.
- [93] arXiv:2408.16283 (replaced) [pdf, html, other]
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Title: Premerger phenomena in neutron-star binary coalescencesComments: 53 pages, 22 figures, 4 tables. To appear as an invited review for a special issue of Universe (Feature Papers 2024 - Compact Objects; Ed. N. Chamel)Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics - Experiment (hep-ex); High Energy Physics - Phenomenology (hep-ph); High Energy Physics - Theory (hep-th)
A variety of high-energy events can take place in the seconds leading up to a binary neutron-star merger. Mechanisms involving tidal resonances, electrodynamic interactions, or shocks in mass-loaded wakes have been proposed as instigators of these precursors. With a view of gravitational-wave and multimessenger astrophysics more broadly, premerger observations and theory are reviewed emphasising how gamma-ray precursors and dynamical tides can constrain the neutron-star equation of state, thermodynamic microphysics, and evolutionary pathways. Connections to post-merger phenomena, notably gamma-ray bursts, are discussed together with how magnetic fields, spin and misalignment, crustal elasticity, and stratification gradients impact observables.
- [94] arXiv:2408.16826 (replaced) [pdf, html, other]
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Title: QSO MUSEUM II: Search for extended Ly$\alpha$ emission around eight $z \sim 3$ quasar pairsEileen Herwig, Fabrizio Arrigoni Battaia, Jay González Lobos, Emanuele P. Farina, Allison W. S. Man, Eduardo Bañados, Guinevere Kauffmann, Zheng Cai, Aura Obreja, J. Xavier ProchaskaComments: 22 pages, 6 figures, 3 appendices; published in A&AJournal-ref: A&A 691, A210 (2024)Subjects: Astrophysics of Galaxies (astro-ph.GA)
Extended Ly$\alpha$ emission is routinely found around single quasars (QSO) across cosmic time. However, few studies have investigated how such emission changes in fields with physically associated QSO pairs, which should reside in dense environments and are predicted to be linked through intergalactic filaments. We present VLT/MUSE snapshot observations (45 min./source) to unveil extended Ly$\alpha$ emission on scales of the circumgalactic medium (CGM) around the largest sample of physically associated QSO pairs to date, encompassing 8 pairs (14 observed QSOs) at $z$~3 with $i$-band magnitude between 18 and 22.75. The pairs are either at close (~50-100 kpc, 5 pairs) or wide (~450-500 kpc, 3 pairs) separation with velocity differences of $\Delta$v < 2000 km s$^{-1}$. We detect extended emission around 12 of the 14 targeted QSOs and investigate the luminosity, size, kinematics and morphology of these Ly$\alpha$ nebulae. On average, they span 90 kpc and are 2.8 $\times 10^{43}$ erg s$^{-1}$ bright. Irrespective of the QSOs' projected distance, the nebulae often (~45 %) extend toward the other QSO in the pair, leading to asymmetric emission whose flux-weighted centroid is at an offset position from any QSO location. We show that large nebulae are preferentially aligned with the large-scale structure as traced by the two QSOs, and conclude that the cool gas (10$^4$ K) in the CGM traces well the direction of cosmic web filaments. Additionally, the radial profile of the Ly$\alpha$ surface brightness around QSO pairs can be described by a power law with a shallower slope (~$-1.6$) with respect to single QSOs (~$-2$), indicative of increased CGM densities out to large radii and/or enhanced contribution from the intergalactic medium (IGM). The sample presented in this study contains excellent targets for ultra-deep observations to directly study filamentary IGM structures in emission.
- [95] arXiv:2409.04405 (replaced) [pdf, html, other]
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Title: Asymptotic-state prediction for fast flavor transformation in neutron star mergersComments: Accepted to PRDSubjects: High Energy Astrophysical Phenomena (astro-ph.HE)
Neutrino flavor instabilities appear to be omnipresent in dense astrophysical environments, thus presenting a challenge to large-scale simulations of core-collapse supernovae and neutron star mergers (NSMs). Subgrid models offer a path forward, but require an accurate determination of the local outcome of such conversion phenomena. Focusing on "fast" instabilities, related to the existence of a crossing between neutrino and antineutrino angular distributions, we consider a range of analytical mixing schemes, including a new, fully three-dimensional one, and also introduce a new machine learning (ML) model. We compare the accuracy of these models with the results of several thousands of local dynamical calculations of neutrino evolution from the conditions extracted from classical NSM simulations. Our ML model shows good overall performance, but struggles to generalize to conditions from a NSM simulation not used for training. The multidimensional analytic model performs and generalizes even better, while other analytic models (which assume axisymmetric neutrino distributions) do not have reliably high performances, as they notably fail as expected to account for effects resulting from strong anisotropies. The ML and analytic subgrid models extensively tested here are both promising, with different computational requirements and sources of systematic errors.
- [96] arXiv:2410.02346 (replaced) [pdf, html, other]
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Title: Effects of grain temperature distribution on organic protostellar envelope chemistryComments: Accepted for publication in A&ASubjects: Astrophysics of Galaxies (astro-ph.GA); Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Context. Dust grains in circumstellar envelopes are likely to have a spread-out temperature distribution. Aims. To investigate how trends in temperature distribution between small and large grains affect the hot corino chemistry of complex organic molecules (COMs) and warm carbon-chain chemistry (WCCC). Methods. A multi-grain multi-layer astrochemical code with an up-to-date treatment of surface chemistry was used with three grain temperature trends: grain temperature proportional to grain radius to the power -1/6 (Model M-1/6), to 0 (M0), and to 1/6 (M1/6). The cases of hot corino and WCCC chemistry were investigated, for a total of six models. The essence of these changes is for the main ice reservoir - small grains - having higher (M-1/6) or lower (M1/6) temperature than the surrounding gas. Results. The chemistry of COMs shows better agreement with observations in models M-1/6 and M1/6 than in Model M0. Model M-1/6 shows best agreement for WCCC because earlier mass-evaporation of methane ice from small grains induces the WCCC phenomenon at lower temperatures. Conclusions. Models considering several grain populations with different temperatures can more precisely reproduce circumstellar chemistry.
- [97] arXiv:2410.11121 (replaced) [pdf, html, other]
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Title: Unveiling dust, molecular gas, and high star formation efficiency in extremely UV bright star-forming galaxies at $z\sim 2.1-3.6$M. Dessauges-Zavadsky, R. Marques-Chaves, D. Schaerer, M.-Y. Xiao, L. Colina, J. Alvarez-Marquez, I. Pérez-FournonComments: 21 pages, 8 figures, 4 tables, 1 Appendix. Astronomy & Astrophysics in pressSubjects: Astrophysics of Galaxies (astro-ph.GA)
We analysed ALMA FIR (1.3 mm) dust continuum and CO emission of 12 starburst galaxies at $z\sim 2.1-3.6$, selected for their extreme brightness in the rest-UV with $M_{\rm UV} = -23.4$ to $-24.7$. We also analysed VLT HAWK-I $H$- and $K_{\rm s}$-band images. The galaxies are characterised by negligible dust attenuations with blue UV spectral slopes ($-2.62$ to $-1.84$), very young stellar populations of $\sim 10$ Myr, and powerful starbursts with a high mean specific star formation rate of $\rm 112~Gyr^{-1}$, placing them $\sim 1.5$~dex above the main sequence at similar redshifts and stellar masses ($M_{\rm stars} \sim (1.5-4.6)\times 10^9~M_{\odot}$). The FIR dust continuum emission revealed in 9 galaxies yields IR luminosities of $(5.9-28.3)\times 10^{11}~L_{\odot}$ and large dust masses barely produced by SNe within the 10~Myr timescale. The CO emission detected in 8 galaxies evidence large molecular gas masses with a mean molecular gas fraction of 82%. The corresponding star formation efficiencies reach $\gtrsim 40$%, with amazingly short molecular gas depletion timescales between <13 Myr and 71 Myr. These unique properties never reported in previously studied galaxies highlight that these galaxies are likely caught at the very beginning of their stellar mass build-up and undergo a very efficient and fast conversion of gas into stars that can only result from the gas collapse within very short free-fall times. We find that the feedback-free starburst model seems to be able to explain the formation of these galaxies. To reconcile the co-spatial FIR dust emission with the UV-bright unattenuated emission, we speculate about radiation-driven outflows that can temporarily remove dust at the location of the starburst and expel dust at large distances in line with the measured large FIR effective radii ($\rm 1.7~kpc - 5~kpc$) in comparison to very compact stellar radii.
- [98] arXiv:2410.14845 (replaced) [pdf, html, other]
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Title: Classification of Wolf Rayet stars using Ensemble-based Machine Learning algorithmsComments: 19 pages, Accepted to APJSubjects: Solar and Stellar Astrophysics (astro-ph.SR); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
We develop a robust Machine Learning classifier model utilizing the eXtreme-Gradient Boosting (XGB) algorithm for improved classification of Galactic Wolf-Rayet (WR) stars based on Infrared (IR) colors and positional attributes. For our study, we choose an extensive dataset of 6555 stellar objects (from 2MASS and AllWISE data releases) lying in the Milky Way (MW) with available photometric magnitudes of different types including WR stars. Our XGB classifier model can accurately (with an 86\% detection rate) identify a sufficient number of WR stars against a large sample of non-WR sources. The XGB model outperforms other ensemble classifier models such as the Random Forest. Also, using the XGB algorithm, we develop a WR sub-type classifier model that can differentiate the WR subtypes from the non-WR sources with a high model accuracy ($>60\%$). Further, we apply both XGB-based models to a selection of 6457 stellar objects with unknown object types, detecting 58 new WR star candidates and predicting sub-types for 10 of them. The identified WR sources are mainly located in the Local spiral arm of the MW and mostly lie in the solar neighborhood.
- [99] arXiv:2410.15913 (replaced) [pdf, html, other]
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Title: The magnetic field in quiescent star-forming filament G16.96+0.27Qi-Lao Gu, Tie Liu, Zhi-Qiang Shen, Sihan Jiao, Julien Montillaud, Mika Juvela, Xing Lu, Chang Won Lee, Junhao Liu, Pak Shing Li, Xunchuan Liu, Doug Johnstone, Woojin Kwon, Kee-Tae Kim, Ken'ichi Tatematsu, Patricio Sanhueza, Isabelle Ristorcelli, Patrick Koch, Qizhou Zhang, Kate Pattle, Naomi Hirano, Dana Alina, James Di FrancescoComments: Accepted by ApJ. 13 pages, 5 figuresSubjects: Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)
We present 850 {\mu}m thermal dust polarization observations with a resolution of 14.4"(~ 0.13 pc) towards an infrared dark cloud G16.96+0.27 using JCMT/POL-2. The average magnetic field orientation, which roughly agrees with the larger-scale magnetic field orientation traced by the Planck 353 GHz data, is approximately perpendicular to the filament structure. The estimated plane-of-sky magnetic field strength is ~ 96 {\mu}G and ~ 60 {\mu}G using two variants of the Davis-Chandrasekhar-Fermi methods. We calculate the virial and magnetic critical parameters to evaluate the relative importance of gravity, the magnetic field, and turbulence. The magnetic field and turbulence are both weaker than gravity, but magnetic fields and turbulence together are equal to gravity, suggesting that G16.96+0.27 is in a quasi-equilibrium state. The cloud-magnetic-field alignment is found to have a trend moving away from perpendicularity in the dense regions, which may serve as a tracer of potential fragmentation in such quiescent filaments.
- [100] arXiv:2411.00072 (replaced) [pdf, html, other]
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Title: TOPO: Time-Ordered Provable OutputsComments: 9 pages, 7 figures. Code available at: this https URLSubjects: Instrumentation and Methods for Astrophysics (astro-ph.IM)
We present TOPO (Time-Ordered Provable Outputs), a tool designed to enhance reproducibility and data integrity in astrophysical research, providing a trustless alternative to data analysis blinding. Astrophysical research frequently involves probabilistic algorithms, high computational demands, and stringent data privacy requirements, making it difficult to guarantee the integrity of results. TOPO provides a secure framework for verifying reproducible data analysis while ensuring sensitive information remains hidden. Our approach utilizes deterministic hashing to generate unique digital fingerprints of outputs, and Merkle Trees to store outputs in a time-ordered manner. This enables efficient verification of specific components or the entire dataset while making it computationally infeasible to manipulate results - thereby mitigating the risk of human interference and confirmation bias, key objectives of blinding methods. We demonstrate TOPO's utility in a cosmological context using TOPO-Cobaya, showcasing how blinding and verification can be seamlessly integrated into Markov Chain Monte Carlo calculations, rendering the process cryptographically provable. This method addresses pressing challenges in the reproducibility crisis and offers a robust, verifiable framework for astrophysical data analysis.
- [101] arXiv:2411.09571 (replaced) [pdf, html, other]
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Title: The Redshift-Space Momentum Power Spectrum III: measuring the growth rate from the SDSSv survey using auto- and cross- power spectrum of the galaxy density and momentum fieldsComments: 15 pages, 8 figures, 2 tables. Published in ApJSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The large-scale structure of the Universe and its evolution over time contains an abundance of cosmological information. One way to unlock this is by measuring the density and momentum power spectrum from the positions and peculiar velocities of galaxies, and fitting the cosmological parameters from these power spectrum. In this paper, we will explore the cross power spectrum between the density and momentum fields of galaxies. We derive the estimator of the density-momentum cross power spectrum multipoles. The growth rate of the large-scale-structure, $f\sigma_8$ is measured from fitting the combined density monopole, momentum monopole and cross dipole power spectrum. The estimators and models of power spectrum as well as our fitting method have been tested using mock catalogues, and we find that they perform well in recovering the fiducial values of the cosmological parameters of the simulations, and we also find that the errors of the parameters can be largely reduced by including the cross-power spectrum in the fit. We measure the auto-density, auto-momentum and cross power spectrum using the Sloan Digital Sky Survey Data Release 14 peculiar velocity catalogue. The fit result of the growth rate $f\sigma_8$ is $f\sigma_8=0.413^{+0.050}_{-0.058}$ at effective redshift $z_{\mathrm{eff}}=0.073$, and our measurement is consistent with the prediction of the $\Lambda$ Cold Dark Matter cosmological model assuming General Relativity.
- [102] arXiv:2411.12022 (replaced) [pdf, html, other]
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Title: DESI 2024 VII: Cosmological Constraints from the Full-Shape Modeling of Clustering MeasurementsDESI Collaboration: A. G. Adame, J. Aguilar, S. Ahlen, S. Alam, D. M. Alexander, C. Allende Prieto, M. Alvarez, O. Alves, A. Anand, U. Andrade, E. Armengaud, S. Avila, A. Aviles, H. Awan, B. Bahr-Kalus, S. Bailey, C. Baltay, A. Bault, J. Behera, S. BenZvi, F. Beutler, D. Bianchi, C. Blake, R. Blum, M. Bonici, S. Brieden, A. Brodzeller, D. Brooks, E. Buckley-Geer, E. Burtin, R. Calderon, R. Canning, A. Carnero Rosell, R. Cereskaite, J. L. Cervantes-Cota, S. Chabanier, E. Chaussidon, J. Chaves-Montero, D. Chebat, S. Chen, X. Chen, T. Claybaugh, S. Cole, A. Cuceu, T. M. Davis, K. Dawson, A. de la Macorra, A. de Mattia, N. Deiosso, A. Dey, B. Dey, Z. Ding, P. Doel, J. Edelstein, S. Eftekharzadeh, D. J. Eisenstein, W. Elbers, A. Elliott, P. Fagrelius, K. Fanning, S. Ferraro, J. Ereza, N. Findlay, B. Flaugher, A. Font-Ribera, D. Forero-Sánchez, J. E. Forero-Romero, C. S. Frenk, C. Garcia-Quintero, L. H. Garrison, E. Gaztañaga, H. Gil-Marín, S. Gontcho A Gontcho, A. X. Gonzalez-Morales, V. Gonzalez-Perez, C. Gordon, D. Green, D. Gruen, R. Gsponer, G. Gutierrez, J. Guy, B. Hadzhiyska, C. Hahn, M. M. S Hanif, H. K. Herrera-Alcantar, K. Honscheid, C. Howlett, D. Huterer, V. Iršič, M. Ishak, R. Joyce, S. Juneau, N. G. Karaçaylı, R. Kehoe, S. Kent, D. Kirkby, H. Kong, S. E. Koposov, A. KreminComments: This DESI Collaboration Key Publication is part of the 2024 publication series using the first year of observations (see this https URL). 55 pages, 10 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We present cosmological results from the measurement of clustering of galaxy, quasar and Lyman-$\alpha$ forest tracers from the first year of observations with the Dark Energy Spectroscopic Instrument (DESI Data Release 1). We adopt the full-shape (FS) modeling of the power spectrum, including the effects of redshift-space distortions, in an analysis which has been validated in a series of supporting papers. In the flat $\Lambda$CDM cosmological model, DESI (FS+BAO), combined with a baryon density prior from Big Bang Nucleosynthesis and a weak prior on the scalar spectral index, determines matter density to $\Omega_\mathrm{m}=0.2962\pm 0.0095$, and the amplitude of mass fluctuations to $\sigma_8=0.842\pm 0.034$. The addition of the cosmic microwave background (CMB) data tightens these constraints to $\Omega_\mathrm{m}=0.3056\pm 0.0049$ and $\sigma_8=0.8121\pm 0.0053$, while further addition of the the joint clustering and lensing analysis from the Dark Energy Survey Year-3 (DESY3) data leads to a 0.4% determination of the Hubble constant, $H_0 = (68.40\pm 0.27)\,{\rm km\,s^{-1}\,Mpc^{-1}}$. In models with a time-varying dark energy equation of state, combinations of DESI (FS+BAO) with CMB and type Ia supernovae continue to show the preference, previously found in the DESI DR1 BAO analysis, for $w_0>-1$ and $w_a<0$ with similar levels of significance. DESI data, in combination with the CMB, impose the upper limits on the sum of the neutrino masses of $\sum m_\nu < 0.071\,{\rm eV}$ at 95% confidence. DESI data alone measure the modified-gravity parameter that controls the clustering of massive particles, $\mu_0=0.11^{+0.45}_{-0.54}$, while the combination of DESI with the CMB and the clustering and lensing analysis from DESY3 constrains both modified-gravity parameters, giving $\mu_0 = 0.04\pm 0.22$ and $\Sigma_0 = 0.044\pm 0.047$, in agreement with general relativity. [Abridged.]
- [103] arXiv:2411.12023 (replaced) [pdf, html, other]
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Title: Exploring HOD-dependent systematics for the DESI 2024 Full-Shape galaxy clustering analysisN. Findlay, S. Nadathur, W. J. Percival, A. de Mattia, P. Zarrouk, H. Gil-Marín, O. Alves, J. Mena-Fernández, C. Garcia-Quintero, A. Rocher, S. Ahlen, D. Bianchi, D. Brooks, T. Claybaugh, S. Cole, A. de la Macorra, Arjun Dey, P. Doel, K. Fanning, A. Font-Ribera, J. E. Forero-Romero, E. Gaztañaga, G. Gutierrez, C. Hahn, K. Honscheid, C. Howlett, S. Juneau, M. E. Levi, A. Meisner, R. Miquel, J. Moustakas, N. Palanque-Delabrouille, I. Pérez-Ràfols, G. Rossi, E. Sanchez, D. Schlegel, M. Schubnell, H. Seo, D. Sprayberry, G. Tarlé, M. Vargas-Magaña, B. A. WeaverComments: This DESI Collaboration Publication is part of the 2024 publication series using the first year of observations (see this https URL). 26 pages, 10 figuresSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
We analyse the robustness of the DESI 2024 cosmological inference from fits to the full shape of the galaxy power spectrum to uncertainties in the Halo Occupation Distribution (HOD) model of the galaxy-halo connection and the choice of priors on nuisance parameters. We assess variations in the recovered cosmological parameters across a range of mocks populated with different HOD models and find that shifts are often greater than 20% of the expected statistical uncertainties from the DESI data. We encapsulate the effect of such shifts in terms of a systematic covariance term, $\mathsf{C}_{\rm HOD}$, and an additional diagonal contribution quantifying the impact of our choice of nuisance parameter priors on the ability of the effective field theory (EFT) model to correctly recover the cosmological parameters of the simulations. These two covariance contributions are designed to be added to the usual covariance term, $\mathsf{C}_{\rm stat}$, describing the statistical uncertainty in the power spectrum measurement, in order to fairly represent these sources of systematic uncertainty. This approach is more general and robust to choices of model free parameters or additional external datasets used in cosmological fits than the alternative approach of adding systematic uncertainties at the level of the recovered marginalised parameter posteriors. We compare the approaches within the context of a fixed $\Lambda$CDM model and demonstrate that our method gives conservative estimates of the systematic uncertainty that nevertheless have little impact on the final posteriors obtained from DESI data.
- [104] arXiv:2411.12027 (replaced) [pdf, html, other]
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Title: Analytical and EZmock covariance validation for the DESI 2024 resultsDaniel Forero-Sánchez, Michael Rashkovetskyi, Otávio Alves, Arnaud de Mattia, Seshadri Nadathur, Pauline Zarrouk, Héctor Gil-Marín, Zhejie Ding, Jiaxi Yu, Uendert Andrade, Xinyi Chen, Cristhian Garcia-Quintero, Juan Mena-Fernández, Steven Ahlen, Davide Bianchi, David Brooks, Etienne Burtin, Edmond Chaussidon, Todd Claybaugh, Shaun Cole, Axel de la Macorra, Miguel Enriquez Vargas, Enrique Gaztañaga, Gaston Gutierrez, Klaus Honscheid, Cullan Howlett, Theodore Kisner, Martin Landriau, Laurent Le Guillou, Michael Levi, Ramon Miquel, John Moustakas, Nathalie Palanque-Delabrouille, Will Percival, Ignasi Pérez-Ràfols, Ashley J. Ross, Graziano Rossi, Eusebio Sanchez, David Schlegel, Michael Schubnell, Hee-Jong Seo, David Sprayberry, Gregory Tarlé, Mariana Vargas Magana, Benjamin Alan Weaver, Hu ZouComments: 23 pages, 5 figures 7 tables, submitted to JCAPSubjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
The estimation of uncertainties in cosmological parameters is an important challenge in Large-Scale-Structure (LSS) analyses. For standard analyses such as Baryon Acoustic Oscillations (BAO) and Full Shape, two approaches are usually considered. First: analytical estimates of the covariance matrix use Gaussian approximations and (nonlinear) clustering measurements to estimate the matrix, which allows a relatively fast and computationally cheap way to generate matrices that adapt to an arbitrary clustering measurement. On the other hand, sample covariances are an empirical estimate of the matrix based on en ensemble of clustering measurements from fast and approximate simulations. While more computationally expensive due to the large amount of simulations and volume required, these allow us to take into account systematics that are impossible to model analytically. In this work we compare these two approaches in order to enable DESI's key analyses. We find that the configuration space analytical estimate performs satisfactorily in BAO analyses and its flexibility in terms of input clustering makes it the fiducial choice for DESI's 2024 BAO analysis. On the contrary, the analytical computation of the covariance matrix in Fourier space does not reproduce the expected measurements in terms of Full Shape analyses, which motivates the use of a corrected mock covariance for DESI's Full Shape analysis.
- [105] arXiv:2411.12895 (replaced) [pdf, html, other]
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Title: Streams and Bubbles: Tidal Shaping of Planetary OutflowsComments: Submitted to AAS journals, comments welcome! Reproduction materials at: this https URLSubjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Planets lose mass to atmospheric outflows, and this mass loss is thought to be central in shaping the bimodal population of gaseous giant and rocky terrestrial exoplanets in close orbits. We model the escape of planetary atmospheres in three dimensional gas dynamic simulations in order to study their emergent morphology. Planetary outflows show a range of shapes from fast, isotropic outflows bounded by bow shocks to slower motion confined to thin streams. We show that a crucial factor is the role of the tidal gravity and orbiting reference frame in which planets lose mass. Flows can be characterized by the dimensionless Rossby number evaluated at the scale of the Hill sphere. Flows with a low Rossby number are significantly deviated and shaped by the stellar gravity, while those with a high Rossby number are comparatively unaffected. Rossby number alone is sufficient to predict outflow morphology as well as kinematic gradients across transit. The known exoplanet population should span a range of outflow Rossby numbers and thus shapes. We can use this information to constrain outflow physics and to inform observing strategies.
- [106] arXiv:2411.13351 (replaced) [pdf, html, other]
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Title: Impact of Jupiter's heating and self-shadowing on the Jovian circumplanetary disk structureComments: 18 pages, 9 Figures, 2 Tables, submitted under reviewSubjects: Earth and Planetary Astrophysics (astro-ph.EP)
Deciphering the structure of the circumplanetary disk that surrounded Jupiter at the end of its formation is key to understanding how the Galilean moons formed. Three-dimensional hydrodynamic simulations have shown that this disk was optically thick and significantly heated to very high temperatures due to the intense radiation emitted by the hot, young planet. Analyzing the impact of Jupiter's radiative heating and shadowing on the structure of the circumplanetary disk can provide valuable insights into the conditions that shaped the formation of the Galilean moons. To assess the impact of Jupiter's radiative heating and shadowing, we have developed a two-dimensional quasi-stationary circumplanetary disk model and used a grey atmosphere radiative transfer method to determine the thermal structure of the disk. We find that the circumplanetary disk self-shadowing has a significant effect, with a temperature drop of approximately 100 K in the shadowed zone compared to the surrounding areas. This shadowed zone, located around 10 Jupiter radii, can act as a cold trap for volatile species such as NH$_3$, CO$_2$ and H$_2$S. The existence of these shadows in Jupiter's circumplanetary disk may have influenced the composition of the building blocks of the Galilean moons, potentially shaping their formation and characteristics. Our study suggests that the thermal structure of Jupiter's circumplanetary disk, particularly the presence of cold traps due to self-shadowing, may have played a crucial role in the formation and composition of the Galilean moons.
- [107] arXiv:1806.07428 (replaced) [pdf, html, other]
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Title: Minimum Quadratic Helicity StatesComments: 15 pages, 3 figuresSubjects: Fluid Dynamics (physics.flu-dyn); Solar and Stellar Astrophysics (astro-ph.SR); Differential Geometry (math.DG)
Building on previous results on the quadratic helicity in magnetohydrodynamics (MHD) we investigate particular minimum helicity states. Those are eigenfunctions of the curl operator and are shown to constitute solutions of the quasi-stationary incompressible ideal MHD equations. We then show that these states have indeed minimum quadratic helicity.
- [108] arXiv:2401.08758 (replaced) [pdf, other]
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Title: DiscoTEX 1.0: Discontinuous collocation and implicit-turned-explicit (IMTEX) integration symplectic, symmetric numerical algorithms with higher order jumps for differential equations I: numerical black hole perturbation theory applicationsComments: 50 pages, 19 figures, 9 tables. Several typos corrected, higher-order results for the computation of energy and angular moment fluxes added. Includes overview of previous numerical methods implemented in the time-domain for the modelling of asymmetric mass ratio inspirals with suitability checks on Table 9. Now first of a series of papers. Comments are welcomeSubjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Numerical Analysis (math.NA); Computational Physics (physics.comp-ph)
Dirac $\delta-$ distributionally sourced differential equations emerge in many dynamical physical systems from machine learning, finance, neuroscience, and seismology to black hole perturbation theory. These systems lack exact analytical solutions and are thus best tackled numerically. We describe a generic numerical algorithm which constructs discontinuous spatial and temporal discretisations by operating on discontinuous Lagrange and Hermite interpolation formulae, respectively. By solving the distributionally sourced wave equation, possessing analytical solutions, we demonstrate that numerical weak-form solutions can be recovered to high-order accuracy by solving a first-order reduced system of ODEs. The method-of-lines framework is applied to the \texttt{DiscoTEX} algorithm i.e. through \underline{dis}continuous \underline{co}llocation with implicit\underline{-turned-explicit} integration methods which are symmetric and conserve symplectic structure. Furthermore, the main application of the algorithm is proved by calculating the amplitude at any desired location within the numerical grid, including at the position (and at its right and left limit) where the wave- (or wave-like) equation is discontinuous via interpolation using \texttt{DiscoTEX}. This is demonstrated, firstly by solving the wave- (or wave-like) equation and comparing the numerical weak-form solution to the exact solution. We further demonstrate how to reconstruct the gravitational metric perturbations from weak-form numerical solutions of a non-rotating black hole, which do not have known exact analytical solutions, and compare them against state-of-the-art frequency domain results. We conclude by motivating how \texttt{DiscoTEX}, and related numerical algorithms, both open a promising new alternative waveform generation route for modelling highly asymmetric binaries and complement current frequency domain methods.
- [109] arXiv:2402.04830 (replaced) [pdf, html, other]
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Title: Closing the Gap Between SGP4 and High-Precision Propagation via Differentiable ProgrammingJournal-ref: Acta Astronautica 226(1) (2025) 8Subjects: Machine Learning (cs.LG); Earth and Planetary Astrophysics (astro-ph.EP)
The Simplified General Perturbations 4 (SGP4) orbital propagation method is widely used for predicting the positions and velocities of Earth-orbiting objects rapidly and reliably. Despite continuous refinement, SGP models still lack the precision of numerical propagators, which offer significantly smaller errors. This study presents dSGP4, a novel differentiable version of SGP4 implemented using PyTorch. By making SGP4 differentiable, dSGP4 facilitates various space-related applications, including spacecraft orbit determination, state conversion, covariance transformation, state transition matrix computation, and covariance propagation. Additionally, dSGP4's PyTorch implementation allows for embarrassingly parallel orbital propagation across batches of Two-Line Element Sets (TLEs), leveraging the computational power of CPUs, GPUs, and advanced hardware for distributed prediction of satellite positions at future times. Furthermore, dSGP4's differentiability enables integration with modern machine learning techniques. Thus, we propose a novel orbital propagation paradigm, ML-dSGP4, where neural networks are integrated into the orbital propagator. Through stochastic gradient descent, this combined model's inputs, outputs, and parameters can be iteratively refined, surpassing SGP4's precision. Neural networks act as identity operators by default, adhering to SGP4's behavior. However, dSGP4's differentiability allows fine-tuning with ephemeris data, enhancing precision while maintaining computational speed. This empowers satellite operators and researchers to train the model using specific ephemeris or high-precision numerical propagation data, significantly advancing orbital prediction capabilities.
- [110] arXiv:2403.19912 (replaced) [pdf, html, other]
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Title: Automated Identification and Segmentation of Hi Sources in CRAFTS Using Deep Learning MethodComments: 8 pages, 8 figuresSubjects: Computer Vision and Pattern Recognition (cs.CV); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Identifying neutral hydrogen (\hi) galaxies from observational data is a significant challenge in \hi\ galaxy surveys. With the advancement of observational technology, especially with the advent of large-scale telescope projects such as FAST and SKA, the significant increase in data volume presents new challenges for the efficiency and accuracy of data this http URL address this challenge, in this study, we present a machine learning-based method for extracting \hi\ sources from the three-dimensional (3D) spectral data obtained from the Commensal Radio Astronomy FAST Survey (CRAFTS). We have carefully assembled a specialized dataset, HISF, rich in \hi\ sources, specifically designed to enhance the detection process. Our model, Unet-LK, utilizes the advanced 3D-Unet segmentation architecture and employs an elongated convolution kernel to effectively capture the intricate structures of \hi\ sources. This strategy ensures a reliable identification and segmentation of \hi\ sources, achieving notable performance metrics with a recall rate of 91.6\% and an accuracy of 95.7\%. These results substantiate the robustness of our dataset and the effectiveness of our proposed network architecture in the precise identification of \hi\ sources. Our code and dataset is publicly available at \url{this https URL}.
- [111] arXiv:2404.15136 (replaced) [pdf, html, other]
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Title: QCD topology and axion properties in an isotropic hot and dense mediumComments: 10 pages, 10 figures; accepted for publication in EPJCSubjects: High Energy Physics - Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE)
We study the QCD topology and axion properties at finite temperature and chemical potential in the framework of the two-flavor Nambu$-$Jona-Lasinio model. We find that the behaviors of the two lowest cumulants of the QCD topological charge distribution and axion properties are highly sensitive to the critical behavior of the chiral phase transition. In particular, the topological susceptibility and the axion mass follow the response of the chiral condensate to temperature and chemical potential, showing that both quantities decrease monotonically with the increment of temperature and/or chemical potential. However, it is important to note that the normalized fourth cumulant behaves differently depending on the temperature. At low temperatures, it is a non-monotonic function of the chemical potential, while at high temperatures, it monotonically decreases. Additionally, its value invariably approaches the asymptotic value of $b_2^{\text {inst }}=-1/12$, predicted by the dilute instanton gas model. We also observe that with the increase in chemical potential at relatively low temperatures, the axion self-coupling constant exhibits a sharp peak around the critical point, which can even be more than twice its vacuum value. After that, the self-coupling drops sharply to a much lower value than its vacuum value, eventually approaching zero in the high chemical potential limit. The finding that the axion self-coupling constant is significantly enhanced in high-density environments near the chiral phase transition could lead to the creation or enhancement of an axion Bose-Einstein condensate in compact astrophysical objects.
- [112] arXiv:2405.08050 (replaced) [pdf, html, other]
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Title: Reconstructions of $f(\mathcal{P})$ and $f(\mathcal{Q})$ gravity models from $(m,n)$-type Barrow Holographic Dark Energy: Analysis and Observational ConstraintsComments: 32 pages, 30 images. Comments are welcomeJournal-ref: International Journal of Geometric Methods in Modern Physics (2024)Subjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO)
In this research, we have reconstructed the extended $f(\mathcal{P})$ cubic gravity and symmetric $f(\mathcal{Q})$ teleparallel gravity from the $(m,n)$-type Barrow Holographic Dark Energy (BHDE) model. We have derived the unknown functions $f(\mathcal{P})$ and $f(\mathcal{Q})$ in terms of $\mathcal{P}$ and $\mathcal{Q}$, assuming a flat, homogeneous, and isotropic universe. To constrain our model parameters, we employed cosmic chronometer datasets and Baryon Acoustic Oscillation datasets, utilizing Markov Chain Monte Carlo (MCMC) method. We analysed the behaviour and stability of each model throughout the universe's evolution by studying crucial parameters such as the deceleration parameter, equation of state (EoS) parameter $\omega_{DE}$, density parameter $\Omega(z)$ and the square of the speed of sound $v_s^2$. Additionally, we explored the cosmographic behaviour by plotting the jerk parameter, snap parameter, and lerk parameter against the redshift. Furthermore, we examined the $\omega'_{DE}-\omega_{DE}$ phase plane, the $(r,s^*)$, $(r,q)$ statefinder parameters, and the $Om(z)$ parameter offers profound revelations about the dynamics of the universe and the distinctive features of dark energy. Our analyses indicated that our model could produce a universe undergoing accelerated expansion with quintessence-type dark energy. These findings contribute to our understanding of the nature of dark energy and the evolution of the cosmos.
- [113] arXiv:2408.13107 (replaced) [pdf, html, other]
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Title: Quarkyonic equation of state with a momentum dependent interaction and neutron star structureComments: 9 pages, 10 figures, 1 table. Comments are welcomeJournal-ref: Nuclear Physics A 1054 (2025) 122982Subjects: Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics - Phenomenology (hep-ph)
The structure and basic properties of dense nuclear matter still remain one of the open problems of Physics. In particular, the composition of the matter that composes neutron stars is under theoretical and experimental investigation. Among the theories that have been proposed, apart from the classical one where the composition is dominated by hadrons, the existence or coexistence of free quark matter is a dominant guess. An approach towards this solution is the phenomenological view according to which the existence of quarkyonic matter plays a dominant role in the construction of the equation of state (EOS). According to it the structure of the EOS is based on the existence of the quarkyonic particle which is a hybrid state of a particle that combines properties of hadronic and quark matter with a corresponding representation in momentum space. In this paper we propose a phenomenological model for quarkyonic matter, borrowed from corresponding applications in hadronic models, where the interaction in the quarkyonic matter depends not only on the position but also on the momentum of the quarkyonic particles. This consideration, as we demonstrate, can have a remarkable consequence on the shape of the EOS and thus on the properties of neutron stars, offering a sufficiently flexible model. Comparison with recent observational data can place constraints on the parameterization of the particular model and help improve its reliability.
- [114] arXiv:2408.13170 (replaced) [pdf, html, other]
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Title: A GPU-accelerated semi-coherent hierarchical search for stellar-mass binary inspiral signals in LISAComments: 15 pages + appendices, 7 figures, submitted to PRDJournal-ref: Phys. Rev. D 110, 103026 (2024)Subjects: General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Searching for gravitational waves from stellar-mass binary black holes with LISA remains a challenging open problem. Conventional template-bank approaches to the search are impossible due to the prohibitive number of templates that would be required. This paper continues the development of a hierarchical semi-coherent stochastic search, extending it to a full end-to-end pipeline that is then applied to multiple mock LISA data streams which include simulated noise. Particle swarm optimization is used as a stochastic search algorithm, tracking multiple maxima of a semi-coherent search statistic defined over source parameter space. The pipeline is accelerated by the use of graphical processing units (GPUs). No prior information from observations by ground-based detectors is used; this is necessary in order to provide advance warning of the merger. We find that the pipeline is able to detect sources with signal-to-noise ratios as low as $\rho\sim 17$, we demonstrate that these searches can directly seed coarse parameter estimation in cases where the search trigger is loud. An example of how the false-alarm probability can be estimated for this type of GW search is also included.
- [115] arXiv:2409.20045 (replaced) [pdf, html, other]
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Title: Bubble wall velocity from number density current in (non)equilibriumComments: v2, 43 pages, 7 figures, major revision, a proof is added for the collision integral to vanish in local dynamical equilibrium, the necessity is introduced for the scalar-wall contribution to the total number density current, the clarification is emphasized for the conservation and violation of total number density current across the shock front and bubble wall, respectivelySubjects: High Energy Physics - Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
Cosmological first-order phase transitions (FOPTs) serve as comprehensive probes into our early Universe with associated generations of stochastic gravitational waves and superhorizon curvature perturbations or even primordial black holes. In characterizing the FOPT, phenomenological parameters like transition temperatures, strength factors, bubble separations, and energy budgets can be easily extracted from the macroscopic equilibrium features of the underlying particle physics models except for the terminal wall velocity of the bubble expansion, making it the last key parameter to be determined most difficultly due to the non-equilibrium nature of the microscopic transition model. In this paper, we propose a new model-independent approach to calculate the bubble wall velocity by virtue of an extra junction condition from the conservation and violation of the total number density current across the shock front (if any) and bubble wall, respectively.
- [116] arXiv:2411.07692 (replaced) [pdf, html, other]
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Title: Crunch from AdS bubble collapse in unbounded potentialsComments: 7+6 pages, 7+7 figures, minor changes, references addedSubjects: General Relativity and Quantum Cosmology (gr-qc); Cosmology and Nongalactic Astrophysics (astro-ph.CO); High Energy Physics - Theory (hep-th)
We consider a scalar field theory with a Minkowski false vacuum and an unbounded (or very deep) true vacuum. We show compelling evidence that an AdS bubble of vanishing total energy, embedded in asymptotically flat spacetime, generically undergoes a spherical collapse which leads to a space-like curvature singularity after the formation of trapped surfaces and apparent horizons. The crunch singularity, which is hided behind an apparent horizon, occurs before the true vacuum is reached, and the existence of a lower bound of the scalar field potential is not a necessary condition for its formation.