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The Material Science Behind A Spacecraft’s Impact Armor Aerospace engineers have to consider numerous factors when designing a spacecraft, but one that comes up more and more often is the need to design against Micro-Meteoroids and Orbital Debris (MMOD). While most designers understand the threat, designing structural solutions capable of withstanding the hypervelocity impacts these undercontrolled pieces of material can cause can take a significant bite out of a mission’s mass budget. A new paper from Binkal Kumar Sharma of the University of Bremen and Harshitha Baskar, an independent researcher, provides a detailed review of cutting-edge options for defending against those deadly particles. Universe TodayRead More →

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In: arXiv

A useful representation of TESS light curves Dovi Poznanski arXiv:2605.05324v1 Announce Type: new Abstract: We present a simple and interpretable representation of TESS light curves designed for large-scale exploratory analysis. Our goal is not to optimize classification performance, but to construct a computationally efficient mapping in which proximity reflects meaningful similarity, without using labels or explicit period information as inputs. We represent each light curve using either quantile graphs or scattering transforms, reduce dimensionality with principal component analysis, and project the resulting features onto a self-organizing map (SOM). We evaluate ~1500 model configurations using a combination of standard embedding diagnostics and a light-curve-shape-based cohesion metric,Read More →

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In: arXiv

Rotational effects in quark stars: comparing different models Adamu Issifu, Andreas Konstantinou, Franciele M. da Silva, Tobias Frederico arXiv:2511.20477v2 Announce Type: replace Abstract: We investigate the rotational properties of self-bound strange quark stars using two representative quark matter equations of state (EOS): the vector MIT bag model and the density-dependent quark mass (DDQM) model. Through general-relativistic calculations of uniformly rotating sequences, we analyze their mass–radius relations, moments of inertia, quadrupole moments, surface redshifts, Keplerian frequencies, and energy components. A central result of this work is the full decomposition of the stellar energy budget in rotating strange stars, separating gravitational, internal, rotational, and binding energy contributions.Read More →

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In: arXiv

Primordial Magnetic Fields at Cosmic Dawn: 21-cm Forecasts with HERA and SKA Keduse Worku, Hector Afonso G. Cruz, Marc Kamionkowski arXiv:2605.05323v1 Announce Type: new Abstract: Primordial magnetic fields (PMFs) can enhance the abundance of low-mass halos during Cosmic Dawn by sourcing additional small-scale matter fluctuations. This enhanced small-scale power can accelerate early galaxy formation, shifting the timing of Lyman-$alpha$ coupling, X-ray heating, and reionization toward earlier times and imprinting correlated signatures on the global and fluctuating 21-cm signals. We extend the fast analytic framework {ttstring zeus21} to include a physically motivated PMF contribution to the linear matter power spectrum, including radiative damping before recombination andRead More →

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In: arXiv

CIGaRS I: Combined simulation-based inference from type Ia supernovae and host photometry Konstantin Karchev, Roberto Trotta, Raul Jimenez arXiv:2508.15899v2 Announce Type: replace Abstract: Using type Ia supernovae as cosmological probes requires empirical corrections that are correlated with their host environment. Here we present a unified Bayesian hierarchical model designed to infer, from purely photometric observations, the intrinsic dependence of the brightness of type Ia supernovae on progenitor properties (metallicity and age), the delay-time distribution that governs their rate as a function of age, and cosmology, as well as the redshifts of all hosts. The model incorporates physics-based prescriptions for star formation and chemical evolution fromRead More →

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In: arXiv

Moving-mesh simulations of spreading dynamics and local electron cooling in structured gamma-ray burst afterglow jets Sayan Kundu, Hendrik van Eerten arXiv:2605.05320v1 Announce Type: new Abstract: We present the results for the dynamics and emission profiles of axi-symmetric numerical simulations of structured gamma-ray burst afterglow jets, computed using the relativistic moving-mesh hydrodynamics code GAMMA. We find that the spreading of jets of average opening angle is moderately impacted by the initial steepness of the angular structure, although the effect disappears once the working surface of the jet substantially exceeds its initial width, and that the travel time of a sound wave across the front surface remainsRead More →

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In: arXiv

On the non-radial oscillations of realistic anisotropic neutron stars: Axial modes Jose F. Rodriguez-Ruiz, L. M. Becerra, F. D. Lora-Clavijo arXiv:2605.06418v1 Announce Type: cross Abstract: Non-radial oscillation modes of neutron stars serve as diagnostics of their internal composition and relativistic structure. In this work, we investigate the perturbations of static and spherically symmetric neutron stars characterized by an anisotropic pressure. Given the background symmetry, perturbations decouple into polar and axial modes. To date, axial modes have remained less explored, primarily because matter and metric perturbations decouple in the isotropic limit. In this work, we provide a consistent treatment of axial modes and demonstrate that pressureRead More →

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In: arXiv

HOLISMOKES XXI: Detecting strongly lensed type Ia supernovae from time series of multi-band LSST-like imaging data — Part II Satadru Bag, Raoul Canameras, Sherry H. Suyu, Stefan Schuldt, Stefan Taubenberger, Irham Taufik Andika, Alejandra Melo, Ming Kei Chan arXiv:2605.05318v1 Announce Type: new Abstract: Strong gravitationally lensed supernovae (LSNe) are rare but extremely valuable probes of cosmology and astrophysics. Prompt identification within the alert streams of time-domain surveys such as the Rubin Legacy Survey of Space and Time (LSST) is essential for timely follow-up observations. In our previous study, Bag et al. (2026), we introduced a deep-learning framework for detecting LSNe Ia directly from multi-band, multi-epochRead More →

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In: arXiv

Perturbations in the parametrized wormhole spacetime and their related quasinormal modes Shauvik Biswas, Sayan Chakrabarti arXiv:2605.05352v1 Announce Type: cross Abstract: We study electromagnetic perturbations and the associated quasinormal modes (QNMs) of parametrized static, spherically symmetric wormhole spacetimes, focusing on Damour-Solodukhin and braneworld geometries as well as their galactic extensions. Using the Bronnikov-Konoplya-Pappas parametrization, we express the metric functions in terms of a compactified radial coordinate and characterize the spacetime through far-field and near-throat parameters. The far-field coefficients govern the asymptotic structure and post-Newtonian behaviour, while the near-throat continued-fraction expansion captures the strong-field geometry near the throat. We first apply the parametrization to isolated wormholes andRead More →

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In: arXiv

Stellar rotation and binaries in open clusters with Gaia DR3 Elena Pancino, Elisabetta Reggiani, Silvia Marinoni, Paola M. Marrese, Deimer Alvarez Garay, Aleksandra Avdeeva, Maite Echeveste, Ellen I. Leitinger, Sneha Nedhath, Sharmila Rani, Nicoletta Sanna, Sara Saracino, Laurenz F. Steinbauer, Alessio Turchi, Vikrant V. Jadhav, Sebastian Kamann, Monica Rainer arXiv:2605.05313v1 Announce Type: new Abstract: Stellar rotation is a fundamental ingredient in shaping the evolution of stars and it can also be used to trace past stellar interactions. Yet, systematic studies of stellar rotation in large samples of stars belonging to different populations have only recently been made possible, thanks to spectroscopic surveys. We profit fromRead More →

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In: arXiv

A preliminary exploration of the effects of baseline length for the LIFE space mission Jonah T. Hansen, Thomas Birbacher, Felix A. Dannert, Philipp Huber, Andrea Fortier, Adrian M. Glauser, Jens Kammerer, Romain Laugier, Lia Sartori, Sascha P. Quanz arXiv:2605.06648v1 Announce Type: new Abstract: By aiming to find and characterise dozens of habitable exoplanets through the technique of nulling interferometry, the LIFE space mission will produce transformational science. One of the key parameters for such an interferometric mission is the nulling baseline length – the distance between nulled apertures, which past studies have assumed to be 10-100m. Advances in planet occurrence statistics and simulation tools allowRead More →

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In: arXiv

Constraints on the inflationary vacuum and reheating era from NANOGrav Debtosh Chowdhury, Rounak Nath, Sudipta Show arXiv:2605.05310v1 Announce Type: new Abstract: NANOGrav and various pulsar timing array experiments recently reported evidence for a common red noise signal across millisecond pulsars. This signal exhibits Hellings-Downs inter-pulsar correlation patterns, providing compelling evidence for a stochastic gravitational wave background (SGWB) signal. In general, such a background can come from several astrophysical and cosmological phenomena. Assuming such SGWB has an inflationary origin, we use latest NANOGrav 15-year dataset to constrain the inflationary parameters e.g., tensor spectral index ($n_t$), tensor-to-scalar ratio ($r$), and explore the implications for the reheating phaseRead More →

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In: arXiv

Fifteen new millisecond pulsars in 47 Tucanae W. Chen, D. Risbud, P. C. C. Freire, A. Ridolfi, E. Barr, M. Kramer, B. Stappers, F. Camilo, F. Abbate, A. Possenti, Y. P. Men, P. V. Padmanabh, S. M. Ransom, L. Vleeschower, V. Venkatraman Krishnan, D. J. Champion, Rene Breton, V. Balakrishnan, S. Buchner arXiv:2605.06492v1 Announce Type: new Abstract: 47 Tucanae is one of the largest, brightest, and closest globular clusters to Earth. It hosts an exotic stellar population with stellar dynamics that indicate a complex evolution history. The cluster contains a large number of X-ray binaries and millisecond pulsars. However, given its large distance relative toRead More →

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In: arXiv

Kinematic Stratification in Extremely Red Quasars Revealed by JWST Jack M. M. Neustadt, Nadia L. Zakamska, Yu-Ching Chen, Andrey Vayner, Fred Hamann, Marie Wingyee Lau, Serena Perrotta, Kate Rowlands, Sylvain Veilleux, Dominika Wylezalek arXiv:2605.05298v1 Announce Type: new Abstract: We analyze the spectra of the central nuclei of extremely red quasars (ERQs) observed as part of the JWST ERS Q3D program. We focus on the complex kinematic structures of the prominent rest-frame optical emission lines. Our modeling allows us to deblend the lines and separate the emission into distinct kinematic components that imply velocity- and density-stratified gas structures on a range of physical scales within theRead More →

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In: arXiv

No model-independent evidence for a peak in binary black hole spin (mis)alignments Noah E. Wolfe, Salvatore Vitale, Michael Zevin arXiv:2605.05300v1 Announce Type: new Abstract: The degree of black-hole spin-orbit misalignment (“tilts”) in the astrophysical population could be a powerful diagnostic to distinguish between binary formation in isolation, in dynamical environments, or in hierarchical triples. However, robust population-level spin tilt measurements are complicated by model misspecification as well as numerical and Poisson variance, ultimately owing to poor single-event constraints on tilts. Motivated by reports of a possible peak in the spin tilt distribution, we analyze the fourth LIGO-Virgo-KAGRA gravitational-wave transient catalog to test for preferred spinRead More →

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In: arXiv

An X-ray and optical spectral study of the changing-look narrow-line Seyfert 1 2MASX J0413-0050 A. Vietri, A. Tortosa, D. Ili’c, S. Ciroi, M. Berton, E. J"arvel"a, C. Ricci, E. Sani, L. Crepaldi, B. Dalla Barba, S. Chen, E. Congiu, P. Cond`o, I. Varglund, G. Rodighiero arXiv:2605.05301v1 Announce Type: new Abstract: Active galactic nuclei (AGN) showing dramatic spectral and flux variations, either due to changes in the accretion rate (changing-state, CS-AGN) of the supermassive black hole or in the line-of-sight column density (changing-obscuration, CO-AGN), have been classified as changing-look (CL) AGN. Here we present a peculiar source, 2MASX J0413-0050, first identified as a narrow-line Seyfert 1Read More →

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In: arXiv

Multi-wavelength outburst activity from EP J174942.2-384834: a very faint X-ray transient discovered by Einstein Probe F. Coti Zelati, A. Marino, Y. L. Wang, M. Veresvarska, N. Rea, S. Guillot, D. A. H. Buckley, N. Rawat, S. E. Motta, Y. Xu, Z. Li, Y. -F. Huang, H. Feng, L. Tao, M. Imbrogno, G. Illiano, M. C. Baglio, H. Q. Cheng, C. C. Jin, H. Sun, W. Yuan, F. Carotenuto, R. P. Fender, A. Coleiro, D. G"otz, H. L. Li, P. Maggi, Y. L. Qiu, J. Wang, L. P. Xin arXiv:2605.05303v1 Announce Type: new Abstract: We report the discovery and multi-wavelength characterization of the Galactic transient EPRead More →

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In: arXiv

From gas to stars along the spiral wave: CO, HCN, and star formation variations across the spiral arms in NGC 4321 and M51 Minou Greve, Lukas Neumann, Mallory Thorp, Dario Colombo, Frank Bigiel, Miguel Querejeta, Sharon E. Meidt, Ashley T. Barnes, Zein Bazzi, Ralf S. Klessen, Adam K. Leroy, Hsi-An Pan, J’er^ome Pety, Marina Ruiz-Garc’ia, Eva Schinnerer, Rowan Smith, Sophia Stuber, Jiayi Sun, Antonio Usero, Thomas G. Williams arXiv:2605.05302v1 Announce Type: new Abstract: Molecular clouds form stars from the interstellar medium via gravitational collapse, following a sequence from low-density gas to high-density cores and eventually the formation of stars. In classical density wave theory, gasRead More →

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In: arXiv

Extended thermodynamics and $P-v$ Criticality of Kalb-Ramond black hole coupled with nonlinear electrodynamics D. V. Singh, S. Upadhyay, P. Paul, K. Myrzakulov arXiv:2605.05281v1 Announce Type: cross Abstract: We present an exact black hole solution in anti-de Sitter (AdS) spacetime with a Kalb-Ramond field coupled to nonlinear electrodynamics (NLED), characterized by mass, magnetic monopole charge, and Lorentz-violating parameters. The geometry admits two horizons (inner and outer) that coalesce into a degenerate horizon at a critical monopole charge. Beyond this critical point, no black hole solutions exist. In the limit of vanishing Lorentz-violating parameters, the solution reduces to the modified Kalb-Ramond and Bardeen black holes, while suitableRead More →

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In: arXiv

The diverse outcomes of binary white dwarf mergers and connections to Galactic LISA sources Kyle Kremer, Katelyn Breivik, Claire S. Ye arXiv:2605.05308v1 Announce Type: new Abstract: In the coming decade, the millihertz gravitational wave observatory LISA will provide the best constraints yet on the tens of thousands of close white dwarf binaries in the Milky Way, yielding unprecedented insights into the most abundant class of compact object binaries. Following inspiral via gravitational wave emission, interacting white dwarf binary pairs can lead to a multitude of outcomes, including AM Canum Venaticorum (AM CVn) binaries, R Coronae Borealis stars, young, rapidly-spinning single white dwarfs, (millisecond) magnetars, andRead More →