Clay weekly context brief for the Astro category (ISO week 2026-W28).

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. Stellar J-Harvesting: a novel angular momentum technosignature and first search in the Kepler field
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2607.07781
   We introduce Stellar J-Harvesting (SJH), a technosignature in which an engineered system extracts rotational angular momentum from a star.
2. Probing the fate of large primordial perturbations with exoplanets
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2606.14827
   We propose ultra-wide-orbit exoplanets as a novel probe of small-scale dark matter objects.
3. Milky Way Near Twins (MWNeTs). I. A Hierarchical Framework for Identifying the Evolutionary Counterparts of the Milky Way
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2607.08336
   The search for Milky Way (MW) analogues has traditionally relied on similarity in a limited set of present-day global properties, including morphology.
4. Deep Spectroscopic Follow-Up of Maisie's Galaxy -- A Typical Galaxy in the Early Universe
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2607.08749
   The first several years of JWST observations have yielded surprisingly large numbers of bright $z>10$ galaxies, with follow-up spectroscopy of many of these sources implying extreme star formation activity and/or AGN content.
5. Earth's Infrared Background: A Physics-Based Null Hypothesis for the Global-Scale Subannual Variability of Outgoing Longwave Radiation
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2503.05288
   Much of the Outgoing Longwave Radiation (OLR) emitted to space can be described as a noisy "background" of random variability.
6. Probing Quadratically Coupled Ultralight Dark Matter with the Laser Interferometer Space Antenna
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2607.08248
   Ultralight dark matter can interact with Standard Model particles via gravitational and non-gravitational interactions.
7. Force convergence in Monte Carlo Lyman-alpha radiative transfer
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2607.08726
   Monte Carlo radiative transfer (MCRT) is widely used to model Lyman-alpha (Lya) resonant-line transport, but convergence is difficult to assess in optically thick media where photons undergo many scatterings before escape.
8. On the Eccentricity Distribution and Tidal Evolution of Transiting Brown Dwarfs
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2607.02682
   Brown dwarfs on short-period orbits populate an intermediate regime between hot Jupiters and tight stellar binaries, lying at the intersection of possible evolutionary avenues.
9. Multipolar Dark Matter Freeze-out in an Early Matter-Dominated Universe
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2607.07956
   The relic abundance of thermal dark matter depends not only on its particle interactions but also on the expansion history of the early Universe.
10. Thermal Sunyaev-Zel'dovich Measurements of Locally Bright Galaxies with ACT DR6: Radio Source Contamination and Excess Compton-y Signal
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2607.08721
   The Planck collaboration found a remarkable power-law relation between stellar mass and the thermal Sunyaev-Zeldovich (tSZ) signal for the Locally Bright Galaxy (LBG) sample, spanning over a decade in stellar mass.
11. Understanding eccentric temperate giants: an in-depth study of the architecture and stellar obliquity of the TOI-2134 system
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2607.01027
   We revisit the TOI-2134 planetary system with three new high-cadence TESS sectors and 98 more spectra.
12. Causal Horizons, Geodesic Completeness and Stability in Slow Contraction Cosmology
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2607.07815
   We show that cosmological models with a semi-infinite phase of slow contraction (ekpyrosis) possess a combination of properties that can address several fundamental problems in cosmology, otherwise faced in contracting de Sitter phases or standard big bang expansion.
13. Detection of the Polycyclic Aromatic Hydrocarbon Phenalene (C$_{13}$H$_{10}$) in the Very Low Luminosity Object (VeLLO) MC27/L1521F
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2607.08699
   To date, 14 polycyclic aromatic hydrocarbons (PAHs) ranging in size from two to seven (including five- and six-membered) carbon rings have been detected in the starless dense core TMC-1 CP within the Taurus molecular cloud.
14. CORALIE radial-velocity search for companions around evolved stars (CASCADES) V. Three planetary companions and achievable precision
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2606.09072
   Aims.
15. Bo\"otes III is a Tidally Disrupting Ultra-Faint Dwarf Galaxy on an Eccentric Polar Orbit
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2607.07803
   We present updated systemic properties of the ultra-faint dwarf galaxy Bo\"otes III from the Southern Stellar Stream Spectroscopic Survey (S$^5$).
16. VAPOLA -- A multi-year, multi-band polarization survey of AGN and Sgr A* at mm wavelengths with ALMA I. Survey Overview and Science-Ready Archival Products
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2607.08657
   The Atacama Large Millimeter/submillimeter Array (ALMA) is the most sensitive interferometric array at millimeter and submillimeter wavelengths.
17. Evolution of a synchronous planet-moon pair due to solar tides.
   Source: astro-ph.EP (Earth and Planetary Astrophysics)
   Link: https://arxiv.org/abs/2604.10781
   Mars' asymmetric figure with two opposing equatorial elevations stems from a frozen tidal bulge raised by a synchronous palaeo-moon Nerio.
18. Multi-Wavelength Signatures of a Giant Cometary Radio Halo in MACSJ0417-1154
   Source: astro-ph.CO (Cosmology and Nongalactic Astrophysics)
   Link: https://arxiv.org/abs/2607.07750
   Galaxy clusters hosting diffuse non-thermal radio emission offer direct insight into plasma processes of the intracluster medium (ICM).
19. Classification of blazars based on data-driven approaches
   Source: astro-ph.GA (Astrophysics of Galaxies)
   Link: https://arxiv.org/abs/2607.08594
   Active galactic nuclei (AGNs), including blazars, exhibit distinctive variability in their optical light curves, making them ideal for classification studies.

Sources in this brief: astro-ph.CO (Cosmology and Nongalactic Astrophysics); astro-ph.EP (Earth and Planetary Astrophysics); astro-ph.GA (Astrophysics of Galaxies).
Selected 19 of 58 available items for this weekly brief.