Hydrogels Could Be Ideal Radiation Protection For Astronauts Hydrogel protection could be crucial for safe human space exploration. Space radiation: the threat is real. Credit: ESA It’s a key problem that will need to be addressed, if humans are to attempt deep-space, long duration missions. Not only is radiation exposure a dangerous health risk to humans, but it also poses a hazard to equipment and operating systems. Now, a team at Ghent University in Belgium are testing a possible solution: 3D printed hydrogels, which could provide deformable layers of water-filled protection. Water acts as a great radiation shield. Relatively dense, the hydrogen-laden H2O molecule canRead More →

Gravitational Waves from Accretion Disks: Turbulence, Mode Excitation and Prospects for Future Detectors Chen Yuan, Vitor Cardoso, Francisco Duque, Ziri Younsi arXiv:2502.07871v1 Announce Type: cross Abstract: We study gravitational-wave emission by turbulent flows in accretion disks around spinning black holes or neutron stars. We aim to understand how turbulence can stochastically excite black hole quasinormal ringing and contribute to a stochastic gravitational-wave background from accretion disks around compact objects. We employ general relativistic magnetohydrodynamic simulations and feed them as the source of the Teukolsky master equation to evaluate the gravitational wave energy spectrum of a single source. The stochastic gravitational wave background from accretion disksRead More →

Fast Radio Bursts as cosmological proxies: estimating the Hubble constant Eduard Fernando Piratova-Moreno, Luz ‘Angela Garc’ia, Carlos A. Benavides-Gallego, Carolina Cabrera arXiv:2502.08509v1 Announce Type: new Abstract: One of the most challenging problems in cosmology is the Hubble tension, a discrepancy in the predicted expansion rate of the Universe. We leverage the sensitivity of the Dispersion Measure (DM) from Fast Radio Bursts (FRBs) with the Hubble factor to investigate the Hubble tension. We build a catalog of 98 localized FRBs and an independent mock catalog and employ 3 methods to calculate the best value of the $H_0$: i) the mean of $H_0$ values obtained through directRead More →

Recovering the structure of debris disks non-parametrically from images Yinuo Han, Mark C. Wyatt, Sebastian Marino arXiv:2502.08584v1 Announce Type: new Abstract: Debris disks common around Sun-like stars carry dynamical imprints in their structure that are key to understanding the formation and evolution history of planetary systems. In this paper, we extend an algorithm (rave) originally developed to model edge-on disks to be applicable to disks at all inclinations. The updated algorithm allows for non-parametric recovery of the underlying (i.e., deconvolved) radial profile and vertical height of optically thin, axisymmetric disks imaged in either thermal emission or scattered light. Application to simulated images demonstrates that theRead More →

Searching for Inflationary Physics with the CMB Trispectrum: 1. Primordial Theory & Optimal Estimators Oliver H. E. Philcox arXiv:2502.04434v2 Announce Type: replace Abstract: The primordial four-point function encodes a wealth of information about the inflationary Universe. Despite extensive theoretical work, most models of four-point physics have never been compared to data. In this series, we conduct a detailed analysis of Cosmic Microwave Background temperature and polarization trispectra, searching for a wide variety of phenomena including local effects, self-interactions, curvatons, DBI inflation, gauge fields, solid inflation, scalar field exchange, spinning massive field exchange, chiral physics, point sources, and gravitational lensing. After presenting a suite of separableRead More →

Dark Matter from Dark Glueball Dominance David McKeen, Riku Mizuta, David E. Morrissey, Michael Shamma arXiv:2406.18635v2 Announce Type: replace-cross Abstract: New gauge forces can play an important role in the evolution of the early universe. In this work we investigate the cosmological implications of a pure Yang-Mills dark sector that is dominantly populated after primordial inflation. Such a dark sector takes the form of a bath of dark gluons at high temperatures, but confines at lower temperatures to produce a spectrum of dark glueballs. These glueballs then undergo a freezeout process such that the remnant population is nearly completely dominated by the lightest state. ToRead More →

Joint Modelling of Astrophysical Systematics for Cosmology with LSST Cosmic Shear Nikolina v{S}arv{c}evi’c, C. Danielle Leonard, Markus M. Rau, LSST Dark Energy Science Collaboration arXiv:2406.03352v3 Announce Type: replace Abstract: We present a novel framework for jointly modelling the weak lensing source galaxy redshift distribution and the intrinsic alignment of galaxies via a shared luminosity function (LF). Considering this framework within the context of a Rubin Observatory’s Legacy Survey of Space and Time (LSST) Year 1 and Year 10 cosmic shear analysis, we first demonstrate the substantial impact of the LF on both source galaxy redshift distributions and the intrinsic alignment contamination. We establish how theRead More →

Galaxy Mergers in the Epoch of Reionization II: Major Merger-Triggered Star Formation and AGN Activities at $z = 4.5 – 8.5$ Qiao Duan, Qiong Li, Christopher J. Conselice, Thomas Harvey, Duncan Austin, Nathan J. Adams, Leonardo Ferreira, Kenneth J. Duncan, James Trussler, Robert G. Pascalau, Rogier A. Windhorst, Benne W. Holwerda, Thomas J. Broadhurst, Dan Coe, Seth H. Cohen, Xiaojing Du, Simon P. Driver, Brenda Frye, Norman A. Grogin, Nimish P. Hathi, Rolf A. Jansen, Anton M. Koekemoer, Madeline A. Marshall, Mario Nonino, Rafael Ortiz III, Nor Pirzkal, Aaron Robotham, Russell E. Ryan Jr, Jake Summers, Jordan C. J. D’Silva, Christopher N. A. Willmer, HaojingRead More →

A Luminous Red Optical Flare and Hard X-ray Emission in the Tidal Disruption Event AT2024kmq Anna Y. Q. Ho (Department of Astronomy, Cornell University), Yuhan Yao (Miller Institute for Basic Research in Science, Berkeley, Department of Astronomy, University of California, Berkeley), Tatsuya Matsumoto (Department of Astronomy, Kyoto University, Hakubi Center, Kyoto University), Genevieve Schroeder (Department of Astronomy, Cornell University), Eric Coughlin (Department of Physics, Syracuse University), Daniel A. Perley (Astrophysics Research Institute, Liverpool John Moores University), Igor Andreoni (University of North Carolina at Chapel Hill), Eric C. Bellm (DIRAC Institute, Department of Astronomy, University of Washington), Tracy X. Chen (IPAC, California Institute of Technology), RyanRead More →

Searching for Hot Water World Candidates with CHEOPS: Refining the radii and analysing the internal structures and atmospheric lifetimes of TOI-238 b and TOI-1685 b J. A. Egger, D. Kubyshkina, Y. Alibert, H. P. Osborn, A. Bonfanti, T. G. Wilson, A. Brandeker, M. N. G"unther, M. Lendl, D. Kitzmann, L. Fossati, C. Mordasini, S. G. Sousa, V. Adibekyan, M. Fridlund, C. Pezzotti, D. Gandolfi, S. Ulmer-Moll, R. Alonso, T. B’arczy, D. Barrado Navascues, S. C. Barros, W. Baumjohann, W. Benz, N. Billot, L. Borsato, C. Broeg, A. Collier Cameron, A. C. M. Correia, Sz. Csizmadia, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline,Read More →

Measuring the Distances to Asteroids from One Observatory in One Night with Upcoming All-Sky Telescopes Maryann Benny Fernandes, Daniel Scolnic, Erik Peterson, Chengxing Zhai, Tyler Linder, Maria Acevedo, Daniel Reichart arXiv:2502.07881v1 Announce Type: new Abstract: Upcoming telescopes like the Vera Rubin Observatory (VRO) and the Argus Array will image large fractions of the sky multiple times per night yielding numerous Near Earth Object (NEO) discoveries. When asteroids are measured with short observation time windows, the dominant uncertainty in orbit construction is due to distance uncertainty to the NEO. One approach to recover distances is from topocentric parallax, which is a technique that leverages the rotationRead More →

A Sizable Discrepancy in Ground-Based JAGB Distances to Nearby Galaxies Gagandeep S. Anand arXiv:2502.07882v1 Announce Type: new Abstract: Recently, Freedman et al. (2024) report agreement of distances derived from the Tip of the Red Giant Branch (TRGB) and the J-Region Asymptotic Giant Branch (JAGB) at the 1$%$ level for both nearby galaxies with ground-based imaging (0.5-4 Mpc) as well distant galaxies with JWST imaging (7-23 Mpc). Here we compare the same ground-based JAGB distances to uniformly reduced space-based optical TRGB distances from the Hubble Space Telescope (HST). We uncover a significant offset between these two distance scales of $Deltamu$ = 0.17 $pm$ 0.04 (stat) $pm$Read More →

Investigating photometric and spectroscopic variability in the multiply-imaged Little Red Dot A2744-QSO1 Lukas J. Furtak (Ben-Gurion University of the Negev), Amy R. Secunda (Flatiron Institute), Jenny E. Greene (, Princeton University), Adi Zitrin (Ben-Gurion University of the Negev), Ivo Labb’e (Swinburne University of Technology), Miriam Golubchik (Ben-Gurion University of the Negev), Rachel Bezanson (University of Pittsburgh), Vasily Kokorev (The University of Texas at Austin), Hakim Atek (Institut d’Astrophysique de Paris), Gabriel B. Brammer (Cosmic Dawn Center), Iryna Chemerynska (Institut d’Astrophysique de Paris), Sam E. Cutler (University of Massachusetts), Pratika Dayal (Kapteyn Astronomical Institute), Robert Feldmann (Universit"at Z"urich), Seiji Fujimoto (The University of Texas at Austin),Read More →

Mapping Synthetic Observations to Prestellar Core Models: An Interpretable Machine Learning Approach T. Grassi, M. Padovani, D. Galli, N. Vaytet, S. S. Jensen, E. Redaelli, S. Spezzano, S. Bovino, P. Caselli arXiv:2502.07874v1 Announce Type: new Abstract: Observations of molecular lines are a key tool to determine the main physical properties of prestellar cores. However, not all the information is retained in the observational process or easily interpretable, especially when a larger number of physical properties and spectral features are involved. We present a methodology to link the information in the synthetic spectra with the actual information in the simulated models (i.e., their physical properties), inRead More →

Prospects for biological evolution on Hycean worlds Emily G. Mitchell, Nikku Madhusudhan arXiv:2502.07872v1 Announce Type: new Abstract: Recent detections of carbon-bearing molecules in the atmosphere of a candidate Hycean world, K2-18 b, with JWST are opening the prospects for characterising potential biospheres on temperate exoplanets. Hycean worlds are a recently theorised class of habitable exoplanets with ocean covered surfaces and hydrogen-rich atmospheres. Hycean planets are thought to be conducive for hosting microbial life under conditions similar to those in the Earth’s oceans. In the present work we investigate the potential for biological evolution on Hycean worlds and their dependence on the thermodynamic conditions. We findRead More →

Building Neutron Stars with the MUSES Calculation Engine Mateus Reinke Pelicer, Nikolas Cruz-Camacho, Carlos Conde, David Friedenberg, Satyajit Roy, Ziyuan Zhang, T. Andrew Manning, Mark G. Alford, Alexander Clevinger, Joaquin Grefa, Roland Haas, Alexander Haber, Mauricio Hippert, Jeremy W. Holt, Johannes Jahan, Micheal Kahangirwe, Rajesh Kumar, Jeffrey Peterson, Hitansh Shah, Andrew W. Steiner, Hung Tan, Yumu Yang, Volodymyr Vovchenko, Veronica Dexheimer, Jorge Noronha, Jaquelyn Noronha-Hostler, Claudia Ratti, Nicol’as Yunes arXiv:2502.07902v1 Announce Type: cross Abstract: Exploring the equation of state of dense matter is an essential part of interpreting the observable properties of neutron stars. We present here the first results for dense matter in theRead More →

Gamma-ray emission from decays of boosted nuclei in proto-magnetar jets Sean Heston, Nick Ekanger, Shunsaku Horiuchi arXiv:2502.07888v1 Announce Type: new Abstract: We examine the detectability of $gamma$-ray emission originating from the radioactive decays of unstable nuclei that are synthesized in relativistic outflows launched in magneto-rotational core-collapse supernovae. The observed lines have enhanced energies due to the Lorentz boosted nuclei and can also be seen until later times due to time dilation of the rest-frame half-lives. We find that instruments like $textit{e-ASTROGAM}$ and $textit{INTEGRAL/SPI}$ are sensitive to these boosted line emissions from 100s of keV to 10s of MeV at a distance of 10 kpc overRead More →

Constraining the history of reheating with the NANOGrav 15-year data Suvashis Maity, Nilanjandev Bhaumik, Md Riajul Haque, Debaprasad Maity, L. Sriramkumar arXiv:2403.16963v2 Announce Type: replace Abstract: Over the last few years, primordial black holes (PBHs) have emerged as a strong candidate for cold dark matter. A significant number of PBHs are produced when the strength of the primordial scalar power spectrum is enhanced on small scales (compared to the COBE normalized values on large scales). Such primordial spectra also inevitably lead to strong amplification of the scalar-induced, secondary gravitational waves (GWs) at higher frequencies. The recent detection of the stochastic gravitational wave background (SGWB) byRead More →

Long-Term X-ray Variability on the Benchmark YSO HL Tau Steven M. Silverberg, Scott J. Wolk, David A. Principe, P. Christian Schneider, Hans Moritz Guenther, Jinyoung Serena Kim, Joel H. Kastner arXiv:2502.07900v1 Announce Type: new Abstract: HL Tau is one of the most well-studied Class I young stellar objects, including frequent observations at near- and mid-infrared, (sub-) millimeter, and X-ray wavelengths. We present the results of an X-ray variability monitoring campaign with XMM-Newton in 2020 and X-ray gratings spectroscopy from Chandra/HETGS in 2018. We find that the X-ray spectrum of HL Tau is consistently hot (with characteristic plasma temperatures $T gtrsim 30$ MK) over 31 epochsRead More →

An Analytically Tractable Marked Power Spectrum Haruki Ebina, Martin White arXiv:2409.17133v2 Announce Type: replace Abstract: The increasing precision of cosmology data in the modern era is calling for methods to allow the extraction of non-Gaussian information using tools beyond two-point statistics. The marked power spectrum has the potential to extract beyond two-point information in a computationally efficient way while using much of the infrastructure already available for the power-spectrum. In this work we explore the marked power spectrum from an analytical perspective. In particular, we explore a low-order polynomial for the mark that allows us to better control the theoretical uncertainties and we show thatRead More →