研究動向

astro-ph.HE2026年8月25日

The impact of circumstellar wind-blown bubbles on the dynamics of pulsar wind nebulae and supernova remnants

Lioni-Moana Bourguinat, Pierrick Martin

The core-collapse supernova explosion of most massive stars is followed by the development of a supernova remnant (SNR) and pulsar wind nebula (PWN) system whose evolution is in part dictated by its surrounding environment. The latter is frequently assumed to be the typical interstellar medium (ISM). However, massive stars emit powerful winds during their lifetime and carve extended circumstellar cavities known as wind-blown bubbles (WBBs). We investigated the impact of WBBs on the dynamics, ene…

詳細を見る →

astro-ph.GAcs.CVcs.LGmath-phphysics.data-an2026年8月25日

Decoupling candidate dual AGN from chance superpositions in the GOTHIC survey via a deep-learning framework

Bhavesh Mukheja, Snehanshu Saha, Anwesh Bhattacharya, Mousumi Das, Françoise Combes, Sudhanshu Barway

Dual active galactic nuclei (DAGN) mark a critical phase in the evolution of merging galaxies and the pairing of supermassive black holes, yet they remain difficult to identify in large imaging surveys because of projection effects and limited spatial resolution. Compact foreground stars and unresolved substructure can mimic dual nuclei through chance superposition, complicating automated detection. We revisit the 46,061 galaxies flagged but rejected as DAGN candidates by the GOTHIC pipeline, pr…

詳細を見る →

hep-phastro-ph.HE2026年8月25日

Searching for Solar-Basin Axionlike-Particle Decay with XMM-Newton Blank-Sky Observations

Bo Zhang, Chi Zhang, Lei Lei, Yang Yu, Guan-Shen Wang, Bing-Yu Su, Lei Feng

Axion-like particles (ALPs) bound in the solar gravitational field form the so-called ALP solar-basin. Since the two-photon decay of non-relativistic particles is approximately isotropic, this population can be searched for using observations in the anti-solar direction. In this work, we propose a search strategy for narrow decay-line signals from the ALP solar basin using \textit{XMM-Newton} blank-sky observations (XMM-BSOs) stacked spectra data taken in directions opposite to the Sun. By joint…

詳細を見る →

astro-ph.GA2026年8月25日

Interplay of Compaction, Quenching, and Black Hole Growth in the Most Massive Galaxies since $z\sim5$: Insights from JWST and Chandra Data

Novan Saputra Haryana, Masayuki Akiyama, Abdurro'uf, Suchetha Cooray, Itsna Khoirul Fitriana, Dian P. Triani, Bovornpratch Vijarnwannaluk, Juan Pablo Alfonzo et al.

The buildup of dense stellar cores is expected to mark an important transition in the star-formation and black-hole growth of massive galaxies. Using spatially resolved spectral energy distribution (SED) fitting of James Webb Space Telescope near-infrared imaging, combined with stacking analysis of Chandra X-ray data, we trace stellar mass buildup and average black hole accretion in the most massive galaxies at $z 4$, indicating that substantial average black-hole growth emerges primarily during…

詳細を見る →

astro-ph.GA2026年8月25日

Comparing the Nebular and Stellar Dust Attenuation Curves in Nearby Star-Forming Galaxies

Jong Chul Lee, Hyunjin Shim, Hyunmi Song, Ho Seong Hwang, Woong-Seob Jeong, Jong-Ho Shinn

Differences in the spatial distributions of stars and ionized gas relative to dust in galaxies imply that stellar and nebular dust attenuation curves need not be identical. Although stellar attenuation curves have been extensively studied, nebular attenuation curves remain less explored. In this work, we investigate nebular attenuation curves using Balmer line ratios for a sample of 90,958 nearby star-forming galaxies from the Sloan Digital Sky Survey with well-constrained stellar attenuation cu…

詳細を見る →

astro-ph.HEastro-ph.GA2026年8月25日

Spatially resolved spectral properties of M87* on event horizon scales

Shan-Shan Zhao, Ru-Sen Lu, Rocco Lico, Yuh Tsunetoe, Sijia Peng

The supermassive black hole at the center of the nearby radio galaxy M87 (M87*) is a prime target for studying black hole physics. Spatially resolved spectral measurements on event-horizon scales can reveal the origin of the emission and probe the plasma and gravitational environment in the immediate vicinity of the black hole. Here, we present an analysis of spectral properties based on nearly simultaneous high-resolution images at 3.5 mm (86 GHz) and 1.3 mm (230 GHz), obtained in 2018 with the…

詳細を見る →

astro-ph.IM2026年8月25日

Validation and extension of the PAWS Zemax model as a first step in the development of a Compact Arrayed Waveguide Stacked Multi-Object Spectrograph (CAWSMOS)

Fabienne Mangelsdorff, Andreas Stoll, Lars Zimmermann, Stefan Lischke, Riya M. Pattery, Kalaga Madhav, Martin M. Roth

The linear size of a bulk optical astronomical spectrograph scales with the diameter of the primary mirror of the corresponding telescope. As modern telescopes continue to increase in aperture size, miniaturization of the spectrograph becomes crucial beyond the offered advantages in terms of multifunctional integration and photon efficiency. The presented concept of development for a Compact Arrayed Waveguide Stacked Multi-Object Spectrograph (CAWSMOS) includes the design of the Arrayed Waveguid…

詳細を見る →

astro-ph.EPastro-ph.GAastro-ph.IM2026年8月25日

Occultation of microlensed images by circum-lens disks: Implications for surveys

Elizabeth Bailey

Microlensing surveys typically apply automated criteria to exclude lightcurves that depart from time-symmetric and achromatic Paczyński curves. In surveys using such automated detection pipelines, occultation of microlensed images by circum-lens material could lead to underdetection or misclassification of ring- or disk-bearing compact object populations. This work characterizes the family of lightcurve morphologies by which uniform thin circum-lens disks of varying size and orientation, and low…

詳細を見る →

astro-ph.HEastro-ph.GAastro-ph.SR2026年8月25日

Linking high-mass X-ray binaries to binary compact object mergers in Milky Way-like galaxies

Felipe Vivanco Cádiz, M. Celeste Artale, Nicola Masetti, Gaston Escobar, Giuliano Iorio, Ankit Kumar, Boyuan Liu, Michela Mapelli et al.

High-mass X-ray binaries (HMXBs) constitute a potential intermediate phase connecting massive stellar binaries to the formation of coalescing binary compact objects (BCOs). Yet, the specific circumstances that allow HMXBs to later develop into merging BCOs are still under debate. In this study, we focus on wind-fed HMXBs and investigate this link by generating synthetic catalogs with the population-synthesis code SEVN and assigning them to a sample of 66 Milky Way-like galaxies. Using stellar pa…

詳細を見る →

astro-ph.EP2026年8月25日

Linear Continuum Modelling to Explain The Majority of Bulk Features of Kuiper Belt Object Spectra

Wesley C. Fraser, Laura E. Buchanan, Ian Wong, Bryan Holler, Michael E. Brown

The first analyses of the James Webb Space Telescope spectra of trans-Neptunian Objects (TNOs) revealed three discrete types of surfaces. This seems to contradict ground-based spectro-photometric datasets, which suggest a continuum of colors with only two surface types. Here we present linear spectral modelling that reconciles these two results. In our model, the sole parameter is the object's optical slope, and the reflectance spectrum at all wavelengths is linearly proportional to that color,…

詳細を見る →

astro-ph.EPastro-ph.SRphysics.geo-ph2026年8月25日

An Evolving Cosmic Shoreline and Sandbar Bounding the Rocky Airless Valley

Barron K. Nguyen, Laura K. Schaefer, Xuan Ji, Christopher A. Theissen, Fei Dai, Bo Peng, Yao Tang, Andrea Zorzi et al.

Recent JWST observations challenge the traditional 'cosmic shoreline' from both sides, revealing thick volatile atmospheres on the hottest close-in 'lava worlds,' where irradiation should drive the most extreme escape, and bare rocky surfaces on cooler terrestrial planets around M dwarfs, where atmospheres would be expected to survive. Using a coupled atmosphere-interior evolution model, we show that atmosphere retention is governed not by a single escape boundary but by two: a hot, outgassing-r…

詳細を見る →

cond-mat.supr-conastro-ph.IM2026年8月25日

Nonequilibrium pulse dynamics and metastable latching in nonlinear kinetic inductance detectors

M. Rouble, C. Albert, P. Day, M. Dobbs, H. G. Leduc, J. Montgomery

Microwave kinetic inductance detectors are typically operated at high readout power to raise the detector signal above system noise. At sufficiently large readout power, the current-dependent kinetic inductance couples the detector response to its readout bias. Using a nonlinear resonator framework and time-domain circuit calculations, we show that the amplitude, shape, and relaxation time of the driven detector's response depend on both the absorbed energy and on the readout bias. Strongly driv…

詳細を見る →

astro-ph.GAastro-ph.HE2026年8月25日

The Local Origin of a Host Dispersion Measure-Stellar Mass Relation in Fast Radio Bursts

Wasundara Athukoralalage, Liam Connor, Peter K. Blanchard, Edo Berger

The origin of fast radio bursts (FRBs) and the relationship to their host galaxy environments remain open questions. Using a sample of 37 FRBs with secure host associations at $z \lesssim 0.25$, and including dwarf, elliptical, and edge-on hosts, we examine the host dispersion measure ($\mathrm{DM_{host}}$) and its dependence on host stellar mass ($M_\star$). We find a statistically significant anti-correlation between the host dispersion measure and host stellar mass (the $\mathrm{DM_{host}}$-$…

詳細を見る →

astro-ph.GA2026年8月25日

The Evolution of Low-Ionization Electron Densities in Galaxies Across Cosmic Epochs

Mabel G. Stephenson, John Chisholm, Alberto Saldana-Lopez, Jorryt Matthee, Alaina Henry, Rohan P. Naidu, Sophia R. Flury, Taylor A. Hutchison et al.

We investigate the low-ionization electron density in the interstellar medium of galaxies across $0$$<$$z$$<$$8$, derived with the [O II]$λ\lambda3727,3730$ and [S II]$λ\lambda6718,6733$ doublets, using both deep JWST NIRCam/grism and NIRSpec/MSA spectroscopy. Along with ancillary density samples from the literature at $0$$<$$z$$<$$6$, we assemble three samples containing a total of 703 galaxies spanning $3.7$$<$$z$$<$$7.8$ at $\langle z\rangle\sim5.6$; 691 galaxies in the luminosity-complete NI…

詳細を見る →

astro-ph.EPastro-ph.GAastro-ph.SR2026年8月25日

An analysis of the Herbig star population and their protoplanetary disks within 1 kpc

L. M. Stapper, M. Vioque, A. J. Winter, D. J. Wilner, J. P. Williams, M. Benisty, A. S. Booth, S. L. Grant et al.

Herbig stars are intermediate mass pre-main sequence stars of 1.5 to $\sim15$~M$_\odot$ and are in between low and high-mass star formation. This work provides a catalog of all 243 known bona-fide Herbig stars with clear infrared excess and in many cases accretion signatures within 1~kpc. It contains archival, recalibrated, and newly derived stellar parameters, accretion rate properties, and disk dust mass measurements. We derive the latter by using newly obtained millimeter photometry and liter…

詳細を見る →

astro-ph.SR2026年8月25日

Periodic activity on the (sub)mm surface of the AGB star Mira A

M. Andriantsaralaza, B. Bojnordi Arbab, W. Vlemmings, T. Khouri, L. Planquart, J. Alcolea, E. Humphreys, S. del Palacio et al.

Evolved stars on the asymptotic giant branch (AGB) lose mass through stellar winds launched from their dynamic extended atmospheres. Recent high-angular-resolution observations of the archetypal AGB star Mira A (o Ceti) have revealed compact hotspots on its submillimetre (submm) surface, whose origin remains unclear. We aim to characterise the submm photosphere of Mira A and investigate the properties and temporal behaviour of the compact hotspots detected on its surface. We analysed 19 epochs o…

詳細を見る →

astro-ph.EPastro-ph.IMphysics.space-ph2026年8月25日

GravDyn: A Python Framework for Gravitational Modeling of Irregular Celestial Bodies Using Polyhedral, mascon, and Series Expansion Methods

Safwan Aljbaae, valerio Carruba, Allan K. de Almeida, Gabriel Antonio Caritá, Antonio F. B. A. Prado, Marcelo L. Mota, Carlos E. Ferreira Lopes

GravDyn is an open-source Python package for computing gravitational potentials and accelerations around irregular celestial bodies. It implements three approaches within the same workflow: the constant-density polyhedral method, a layered mascon approximation based on tetrahedral decomposition, and the Potential Series Expansion Method (PSEM). The package handles shape-model preprocessing, builds the selected gravity representation, and evaluates potentials and accelerations efficiently. The th…

詳細を見る →

astro-ph.HE2026年8月25日

Cows, Tasmanian Devils, and Other Mysteries: Diversity and Origins of Luminous Fast Blue Optical Transients

Anna Y. Q. Ho, Wenbin Lu

By repeatedly mapping the sky, optical telescopes have unveiled a diverse landscape of transients, ephemeral celestial events arising from the destruction of stars and stellar remnants. In this review, we focus on a recently identified phenomenon referred to as luminous fast blue optical transients (LFBOTs) and typified by the transient AT2018cow ("The Cow"). AT2018cow was distinguished by luminous emission at X-ray and radio wavelengths in addition to luminous, rapidly evolving, and blue optica…

詳細を見る →

astro-ph.HEastro-ph.SR2026年8月25日

Sub-Millisecond Pulsars: Missing or Impossible?

T. M. Tauris, V. Venkatraman Krishnan, R. Senzel, P. C. C. Freire, S. M. Ransom, A. Papitto, C. A. N. Biscio, N. Langer et al.

The minimum spin period attainable by a neutron star has been debated since the discovery of the first millisecond pulsar in 1982. A neutron star rotating faster than 1 ms would have far-reaching implications for the dense-matter equation of state, gravitational-wave emission, and the physics of accretion and spin-up. Yet despite the discovery of over 700 millisecond pulsars with spin periods between 1.4 and 10 ms, no sub-millisecond pulsar has been identified. Here we review the physical and ob…

詳細を見る →

astro-ph.EPastro-ph.GA2026年8月25日

The Highly Unusual Behavior and Chemical Composition of Interstellar Comet 2I/Borisov

Allison N. Bair, David G. Schleicher, Theodore Kareta, Matthew M. Knight, Michael S. P. Kelley

We report on imaging, spectroscopy, and narrowband photometry of interstellar comet 2I/Borisov obtained at Lowell Observatory from 2019 September 13 to December 16. We measured chemical composition on four nights before perihelion, from October 4 to November 25 (2.466 to 2.028 au), with CN detections on all nights. Our measurements from October 27 represent the earliest reported detections of C$_2$ and C$_3$, where C$_2$-to-CN and C$_3$-to-CN log production rate ratios were $-$0.7 and $-$1.3, re…

詳細を見る →

astro-ph.SR2026年8月25日

A giant magnetic eruption from the asymptotic giant branch star Mira A

W. Vlemmings, M. Andriantsaralaza, B. Bojnordi Arbab, T. Khouri, B. Lankhaar, L. Planquart, E. De Beck, S. Del Palacio et al.

Mass loss during the advanced evolutionary stages of low- and intermediate-mass stars is traditionally attributed to dust-driven winds, whereas the influence of magnetic fields remains poorly constrained. However, recent observations show massive directional mass ejections from the nearby asymptotic giant branch (AGB) star Mira~A that appear not to be driven by radiation pressure on the dust. We observationally investigate whether magnetic fields are responsible for the mass loss ejections from…

詳細を見る →

astro-ph.GA2026年8月25日

Cool CGM MgII Absorption Across the Star-Forming, Green Valley, and Quiescent Transition

Simon Xinlin Wu, Rongmon Bordoloi, Robert A. Simcoe, Andrew J. Fox, Jessica K. Werk, Jason Tumlinson, J. Xavier Prochaska

We investigate the distribution and kinematics of cool circumgalactic medium (CGM) gas across the star-forming to quiescent transition using MgII absorption for 716 galaxies spanning $0.07<z<2.7$ (169 new and 547 archival galaxies). To compare galaxies uniformly across 10 billion years of cosmic time, we introduce a star-formation offset metric ($σ_{\mathrm{SFO}}$), which measures a galaxy's deviation from the star-forming main sequence of its epoch. A key advantage of $σ_{\mathrm{SFO}}$ is its…

詳細を見る →

astro-ph.IMastro-ph.HEgr-qc2026年8月25日

A General Response Theory for Closure Phases through Visibility Nulls and Image Structure

Shokoufe Faraji, Avery E. Broderick

Closure phase is robust to station based phase errors, yet its connection to image structure is often interpreted only qualitatively and a nonzero closure phase is still interpreted mainly through qualitative symmetry arguments or source specific models. We develop, to our knowledge, the first unified response theory for an arbitrary brightness distribution and an arbitrary zero free observing triangle. Away from visibility zeros, closure phase is naturally a log-visibility observable. This stru…

詳細を見る →

astro-ph.SRastro-ph.IM2026年8月25日

Agentic Active Learning Meets Visual Embeddings: Finding Anomalies among 370 000 Variable Stars from ASAS-SN

Milan Pesta, Yuan-Sen Ting

Unusual light-curve morphologies can point to rare physical configurations or new phenomena, but automatic searches for anomalies are often dominated by artifacts. Separating genuine anomalies from false positives has traditionally required manual vetting, which does not scale to modern surveys. We present an active learning framework for detecting anomalies in samples of periodic variable stars, with the vetting delegated to multimodal large language model agents. The initial ranking comes from…

詳細を見る →

astro-ph.EP2026年8月25日

Quantitative Links between Formation and Atmospheric Composition for Giant Planets

Yayaati Chachan, Ruth Murray-Clay, Jonathan J. Fortney

Precise atmospheric abundances of giant exoplanets are becoming increasingly prevalent and there is a need to systematically convert these measurements into metrics that inform us about the planets' accretion history. We present a quantitative framework for relating atmospheric composition to the accretion of metals and primordial gas. This includes i) new relations that simplify and generalize the connection between atmospheric metallicity and metal mass fraction, ii) methods for inferring the…

詳細を見る →

astro-ph.HEastro-ph.GAastro-ph.SR2026年8月25日

Signatures of Compact Object Mergers Inside Stars in AGN Disks

Matteo Cantiello, Alexander J. Dittmann, Saavik Ford, Barry McKernan, Carlos Palenzuela, Rosalba Perna, Taeho Ryu

Disks of gas accreting onto supermassive black holes, powering active galactic nuclei (AGN), can capture stars from nuclear star clusters or form stars in situ via gravitational instability. The dense, hot disk environment can drive rapid accretion onto embedded stars, dramatically altering their evolution. Models predict that, for sufficiently rapid accretion, fresh gas replenishes hydrogen in stellar cores as quickly as it is burned, and the stars reach a quasi-steady state. Here we study enco…

詳細を見る →

astro-ph.EP2026年8月25日

WASP-12b Exhibits Persistent In-Transit H$α$ Absorption

Shreyas Vissapragada, Fabienne Nail, Morgan MacLeod, Adam Jensen, Stefan Czesla, Mercedes Lopez-Morales, Jea Adams Redai, Kevin N. Ortiz Ceballos et al.

High-resolution H$α$ and He 10830 Å transit spectroscopy can trace the extended upper atmospheres of exoplanets, typically revealing excess in-transit absorption that occurs in the planet's rest frame. However, hydrodynamical simulations predict that absorption should not strictly follow the planet's orbital motion if gas quickly escapes the planetary Roche lobe and shears into tidal tails. The ultra-hot Jupiter WASP-12b fills an exceptionally large fraction of its Roche lobe ($R_p/R_\mathrm{Roc…

詳細を見る →

astro-ph.GAastro-ph.COastro-ph.HE2026年8月25日

More Numerous and Bluer: Companions of the Brightest Little Red Dots Differ from Control Galaxies at $>3σ$, Hinting at Synchronized Black Hole Seed Formation

Fabio Pacucci, C. Megan Urry

The Little Red Dots (LRDs) are a population of compact, red sources, detected abundantly at $4 \lesssim z \lesssim 9$. While their nature is still debated, many models suggest they are powered by accreting massive black holes. Multiple studies have detected blue companions in their vicinity, motivating our analysis: we compare $253$ LRDs uniformly selected across several JWST deep fields against $>7000$ matched controls in the same mosaics. We find that $27.7\%$ of the brightest LRD quartile hos…

詳細を見る →

astro-ph.GA2026年8月25日

A simulation-based quality-control framework for the broad-line region radius-luminosity relation

Juri Wladimir Seib, Francisco Pozo Nuñez, Sarah Elena Ivana Bosman

The broad-line region (BLR) radius-luminosity (R-L) relation underpins single-epoch black hole mass estimates in active galactic nuclei (AGN). The published Hβsample is heterogeneous in observational quality, and it remains unclear how much of its scatter is intrinsic rather than caused by systematics in lag recovery. We quantify the contribution of unreliable lag recovery to the observed scatter of the HβR-L relation and provide tools for quality control. We compile a publicly available databas…

詳細を見る →

astro-ph.GAastro-ph.HE2026年8月25日

Spin inference with the Black Hole Explorer. I. Fisher information matrix forecast

Joseph R. Farah, Daniel C. M. Palumbo, Michael D. Johnson, Dominic O. Chang

General relativity predicts the presence of a thin, bright ring of light superimposed on the image of a black hole (the ``photon ring''), whose geometry is sensitive to the spin of the black hole. Detecting this photon ring in observations of nuclear supermassive black holes would yield insight into gravity in the strong-field regime as well as their growth histories. The Black Hole Explorer (BHEX) is a mission being developed to detect the photon ring for the first time, raising the question of…

詳細を見る →