Clay weekly context brief for the Astro category (ISO week 2026-W37).

Clay tracks publications from the Astro feed list. Below are recent items from this category, each with its source and a short description of what the publication covers when one is available in the source feed.

Recent publications:
1. Properties of Seasonal Ice at Sisyphi Cavi and Implications for Current Modification of Martian Gullies
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2609.03885
   Martian gullies are geologically recent landforms that may form either through liquid-water activity and/or through processes involving CO2 ice.
2. The Zero-Age Massive Stellar Population of W49A from VLA Observations
   Source: astro-ph.SR (Solar and Stellar Astrophysics)
   Link: https://arxiv.org/abs/2608.05453
   We use all-configuration VLA data at 3.3 cm with a physical resolution of ~2000 AU to infer the embedded zero-age massive stellar population of the W49A protocluster, as traced by its compact, ultracompact (UC), and hypercompact (HC) H II regions.
3. Analytical sensitivity curves of the second-generation time-delay interferometry
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2511.01330
   Forthcoming space-based gravitational-wave (GW) detectors will employ second-generation time-delay interferometry (TDI) to suppress laser frequency noise and achieve the sensitivity required for GW detection.
4. Non-extensive entropy signatures in compact star
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2609.03237
   The non-extensive entropy models applied to the black-hole horizon are connected to the generalized Einstein--Hilbert action, $f(R)$, via the Wald entropy formalism.
5. Ionized Nebulae Around Two New Symbiotic Stars: GR Cygni and [D75] 141
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2609.04036
   In the course of selecting targets for a spectroscopic survey of faint planetary-nebula nuclei, we encountered two anomalous cases of late-type variable stars surrounded by nebulosities discovered by amateur astronomers.
6. Spectral Hierarchy of the Cosmic Web
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2603.15834
   We introduce a spectral hierarchy of cosmic-web classifications obtained by applying simple scale-weighting kernels to the density field before performing a standard eigenvalue-based web classification.
7. Systematic and Statistical Properties of Prominence Eruptions on the M-dwarf YZ CMi
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2608.30243
   M-dwarfs produce frequent flares, and their associated mass ejections are expected to significantly affect the habitability of close-in exoplanets.
8. Sensitivity of Neutron Star Observables to Transition Density in Hybrid Equation-of-State Models
   Source: astro-ph.SR (Solar and Stellar Astrophysics)
   Link: https://arxiv.org/abs/2604.11046
   We investigate how the transition density \(\rho_{tr}\) affects hybrid constructions of the neutron-star equation of state (EoS) in which a nucleonic description at low densities is matched to a model-agnostic high-density extension based on a speed-of-sound parametrization.
9. The promise of self-supervised and active learning for Strong Lens discovery: Astronomaly applied to KiDS
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2609.00154
   Strong gravitational lenses (SGLs) are rare systems whose discovery currently relies primarily on supervised machine learning methods trained on large simulated datasets.
10. DANSur_HM: Modularly incorporating higher modes in a deep learning based gravitational-wave surrogate
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2609.03025
   Numerical relativity (NR) simulations provide the most faithful representation of the gravitational waves (GWs) emitted by binary black hole (BBH) systems during merger.
11. Morphology of Radio Sources in Representation Space
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2609.03779
   Understanding radio source morphologies and their classification remains challenging.
12. Ridged Lagrangian Perturbation Theory (RLPT)
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2603.13106
   Galaxy surveys demand fast large-scale structure forward models that preserve large-scale phases while providing realistic nonlinear morphology at fixed force resolution.
13. ThousandWorlds: A benchmark for climate emulation of potentially habitable exoplanets
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2606.18338
   The search for life beyond Earth will depend on detecting faint signatures in the atmospheres of potentially habitable exoplanets.
14. SN 2021pfs: A Type Ia Supernova Likely Affected by Progenitor Metallicity, as Revealed by Comparison with Its Twin Counterpart
   Source: astro-ph.SR (Solar and Stellar Astrophysics)
   Link: https://arxiv.org/abs/2608.19929
   We present extensive photometric and spectroscopic observations of the normal type Ia supernovae (SNe Ia) 2021pfs, which occurred in the Seyfert 2 galaxy NGC 5427 at a redshift 0.009.
15. Radio measurements of air showers with the IceCube-Gen2 surface prototype station at the Pierre Auger Observatory
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2608.30781
   The design of the IceCube-Gen2 observatory, proposed as a next-generation extension of IceCube, includes a surface array consisting of scintillators and radio antennas.
16. Strong Constraints for Line Signals from Dark Matter Annihilation in Sub-halo
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2609.03016
   We present a dedicated search for monochromatic gamma-ray emission from a recently proposed nearby dark matter subhalo candidate.
17. NGC 1901: A new benchmark cluster for gyrochronology in the TESS Southern continuous viewing zone
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2609.03310
   We use Gaia DR3 astrometry and TESS time-series photometry to study NGC 1901, a sparse open cluster in the TESS Southern continuous viewing zone, that has been neglected due to its proximity on the sky to the Large Magellanic Cloud.
18. Dark Matter Recoupling
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2603.09969
   In the late Universe, and on cosmological scales, dark matter is conventionally assumed to be collisionless, as a consequence of the strong existing bounds on dark matter interactions at the Cosmic Microwave Background last-scattering surface.
19. Resolving satellite-in situ mismatches in Net Primary Production using high-frequency in situ bio-optical observations in the subpolar Northwest Atlantic
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2604.08634
   Net primary productivity (NPP) plays a central role in biological carbon pump (BCP) and global carbon cycling, but NPP estimates in high-latitude regions remain highly uncertain despite their disproportional contribution to the global carbon sink.
20. Constraining the origin of magnetic white dwarfs
   Source: astro-ph.SR (Solar and Stellar Astrophysics)
   Link: https://arxiv.org/abs/2412.05400
   The origin of magnetic white dwarfs (MWDs) has been a long-standing puzzle.
21. OpenCosmo: Community Portal and Analysis Framework for Flagship Cosmological Simulations
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2607.16059
   Cosmology is a precision observational science, and large simulations are necessary components of many analyses.
22. Tidally-enhanced resonances in extreme-mass-ratio inspirals: A tertiary path to chaos
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2609.03007
   Extreme-mass-ratio inspirals (EMRIs) provide a unique laboratory for probing strong-field gravity and complex relativistic dynamics.
23. Multi-epoch Detection of an Ultra-fast Inflow in ESP 39607: Evidence for an Accretion Cascade
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2609.03019
   We present simultaneous XRISM, XMM-Newton, and NuSTAR observations of ESP 39607, a Seyfert 2 galaxy at $z = 0.201$.
24. Weibel Instability-Driven Seed Magnetic Fields during Reionization
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2603.03608
   Cosmological reionization was a highly out-of-equilibrium event that affected every parcel of the intergalactic medium, making it a candidate for astrophysical generation of intergalactic magnetic fields.
25. The Ophiuchus DIsc Survey Employing ALMA (ODISEA). Substructures as a function of SED Class and disc mass in 100 systems
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2604.19246
   Current high-resolution studies of protoplanetary discs are biased toward small samples of the brightest (flux > 50 mJy at 225 GHz) and largest systems.
26. Direct Four-Spacecraft Measurement of Reconnection Exhaust Thickness in the Solar Wind
   Source: astro-ph.SR (Solar and Stellar Astrophysics)
   Link: https://arxiv.org/abs/2609.03088
   The thickness of a reconnecting solar wind current sheet is normally inferred from a single spacecraft as the product of the boundary-normal speed and the crossing duration.
27. DANTE: A Reference-Guided Unsupervised Pipeline for Extended-Transient Anomaly Characterization in LIGO O4a
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2606.25702
   The analysis of gravitational-wave detector data during the fourth observing run (O4) requires robust methods to distinguish stationary instrumental noise from non-stationary transients (glitches).
28. Sub-TeV Singlino Dark Matter in light from Sagittarius A$^\ast$ and LUX-ZEPLIN Nuclear-Recoil Event
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2609.02994
   We investigate the impact of a dark matter density spike surrounding the Milky Way's supermassive black hole (SMBH) on the detectability of Singlino-dominated neutralino dark matter within the Next-to-Minimal Supersymmetric Standard Model (NMSSM).
29. The scarcity of white dwarf-brown dwarf binaries in the solar neighbourhood: A population synthesis study
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2609.03017
   White dwarf--brown dwarf (WD--BD) binaries are intrinsically rare systems that provide a unique opportunity to study binary evolution and the formation of substellar companions.
30. OmniCosmos: Transferring Particle Physics Knowledge Across the Cosmos
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2512.24422
   Foundation models build an effective representations of data that can be deployed on diverse downstream tasks.

Sources in this brief: astro-ph.CO (Cosmology and Nongalactic Astrophysics); astro-ph.EP (Earth and Planetary Astrophysics); astro-ph.GA (Astrophysics of Galaxies); astro-ph.HE (High Energy Astrophysical Phenomena); astro-ph.IM (Instrumentation and Methods for Astrophysics); astro-ph.SR (Solar and Stellar Astrophysics).
Selected 30 of 342 available items for this weekly brief.