Clay weekly context brief for the Astro category (ISO week 2026-W36).

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. The Stellar Observations Network Group (SONG) -- A Legacy Archive of Stellar Time-Domain Spectroscopy
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2607.02775
   The Stellar Observations Network Group (SONG) network has operated for more than a decade, providing long-baseline, high-cadence spectroscopic observations of bright stars and the Sun.
2. Dynamical friction on black holes in scalar field environment
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2608.28029
   Astrophysical black holes exist within non-vacuum environments, and their motion through these environments generically result in a force on these black holes through processes such as dynamical friction and Bondi accretion.
3. DESI Data Release 1: Stellar Catalogue
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2505.14787
   In this paper we present the stellar Value-Added Catalogue (VAC) based on the DESI Data Release 1.
4. Separate universe in multifield inflation: a phase-space approach
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2504.11929
   In this article we extend a study of the validity conditions of the separate-universe approach of cosmological perturbations to models of inflation with multiple fields.
5. Assessing astrophysical foreground subtraction in DECIGO using compact binary populations inferred from the first part of the LIGO-Virgo-KAGRA's fourth
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2601.18378
   Detecting the stochastic gravitational wave background (SGWB) from our Universe under the inflationary era is one of the primary scientific objectives of DECi-hertz Interferometer Gravitational wave Observatory (DECIGO), a space-borne gravitational wave detector sensitive in the 0.1Hz frequency band.
6. Dynamically driven collapse of a thermally stable accretion disk in a nova-like system
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2608.27878
   While standard disk instability theory predicts thermal-steady, outburst-free disks in nova-like variables due to their high mass transfer rates, mass transfer variations are prevailingly invoked to explain the occasional flaring/fading phenomena observed in these systems.
7. An All-Sky Catalog of 6.5 Million Primary Red Clump Stars from Gaia DR3 XP Spectra
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2608.28522
   Red clump (RC) stars are excellent standard candles for mapping the three-dimensional structure of the Milky Way.
8. Fast and efficient nested sampling with BEST
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2608.28514
   Nested sampling is widely used for Bayesian evidence computation, but its intrinsically sequential structure limits how efficiently it can exploit modern vectorised likelihoods and emulators.
9. Status of BICEP Array and Integration of the 220/270 GHz Receiver
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2608.25015
   Measurements of the polarization of the cosmic microwave background are critical for modern cosmology as they constrain the physics of the early universe and cosmic inflation.
10. JUG: JAX-based Unified pulsar timinG
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2608.27786
   We present JUG (JAX-based Unified pulsar timinG), a JAX-based, fully independent pulsar timing package emphasising speed and ease of use, designed to confidently handle the increasingly large and complex pulsar timing array datasets that are being created in the pulsar timing field.
11. Relativistic outflows power a quasi-periodic eruption: constraints on energetics, mass loss, and emission mechanisms
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2608.28507
   Quasi-periodic eruptions (QPEs) are recurring bursts of X-ray radiation originating from supermassive black holes (SMBHs).
12. The Canadian Galactic Emission Mapper: A New 8-10 GHz Telescope to Map the Polarization of the Northern Sky
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2608.28159
   The Canadian Galactic Emission Mapper (CGEM) radio telescope is mapping polarized Galactic foregrounds from 8-10 GHz to aid in the search for B-modes in the Cosmic Microwave Background (CMB).
13. A bestiary of low-level electrical artifacts in SPHEREx flight data
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2608.09862
   SPHEREx, NASA's all-sky spectrophotometric survey mission, maps the sky in 102 spectral channels from 0.75 um to 5.0 um at 6.15'' resolution from low-Earth orbit using a custom readout of six HAWAII-2RG detectors.
14. PolPy: A universal tool for X-ray/gamma-ray polarimetry using common data format standards
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2608.27775
   X-ray/gamma-ray polarimetry has been a rapidly developing field in recent years.
15. On the Origin of a Dusty Circumstellar Medium around Red Supergiants
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2608.28344
   Red supergiant (RSG) stars are widely recognized as significant sources of dust, enriching the interstellar medium.
16. Creation of an inflationary epoch from an Emergent Universe through quantum tunneling
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2608.27597
   We consider that the very early Universe was well described by an Emergent Universe, whose geometry was that of a static and classically stable Einstein Universe, which is possible in certain Two Measures Theories (TMT).
17. Qualification pathways for Photonic Integrated Circuits in Astrophotonic Space Missions
   Source: astro-ph.IM (Instrumentation and Methods for Astrophysics)
   Link: https://arxiv.org/abs/2608.00834
   Photonic integrated circuits (PICs) promise order-of-magnitude reductions in the size, weight and power (SWaP) of optical subsystems for astronomy, planetary and Earth-observation missions, yet no PIC-specific space-qualification standard exists.
18. A Similarity Theorem and Its Breakdown in Atomic Black Hole Accretion
   Source: astro-ph.HE (High Energy Astrophysical Phenomena)
   Link: https://arxiv.org/abs/2608.28587
   Atomic gas in a point-mass potential possesses an exact similarity that survives time dependence, two-body atomic microphysics, and a specified class of radiation and feedback laws.
19. From Inspiral to Expansion: The Wake-Driven Torque on Binary Black Holes in Gaseous Medium
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2608.27970
   Binary black holes (BBHs) in gaseous medium, such as active galactic nucleus (AGN) disks, are important gravitational-wave sources, yet the gas-driven torque that governs their orbital evolution remains to be fully understood.
20. The Limited Lifetime of Self-Gravitating Accretion Disks In Galactic Centers
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2608.27586
   Globally self-gravitating accretion disks in active galactic nuclei (AGN) have been frequently discussed in the literature, but never observed.

Sources in this brief: astro-ph.CO (Cosmology and Nongalactic Astrophysics); astro-ph.GA (Astrophysics of Galaxies); astro-ph.HE (High Energy Astrophysical Phenomena); astro-ph.IM (Instrumentation and Methods for Astrophysics).
Selected 20 of 77 available items for this weekly brief.