研究動向

astro-ph.SRastro-ph.EP2026年8月10日

Gas Flows and Mass Accretion Rates in Eight Dippers: HD 142666, HD 143006, HD 145718, V935 Sco, DoAr 25, EPIC 204638512, EPIC 205151387, and EPIC 203850058

Michael L. Sitko, Ray W. Russell, Korash D. Assani, Lucia Villanueva, Jesus Hernandez

One of the scenarios used to explain the dipper phenomenon in stars is having the innermost disk regions being close to the line of sight to the star - inclined greater than 60 degrees - regardless of the inclination of the outermost disk ("mis-aligned" or "broken" disks). If the dust and gas in these disks sample the same material, edge-on disks will be viewed through larger column densities of gas and dust than the average disk. We have examined inter-night variability of eight Kepler-discover…

詳細を見る →

cs.CReess.SPphysics.space-ph2026年8月10日

Treating Statewide CORS Networks as Spatially Distributed Sensors for GNSS Integrity Monitoring under Unintentional and Deliberate Threats

Minhaj Uddin Ahmad, Sagar Dasgupta, Muhammad Sami Irfan, Mizanur Rahman, Mashrur Chowdhury, Thejesh Bandi

State departments of transportation (DOTs) in the United States increasingly rely on statewide continuously operating reference station (CORS) networks to support high-precision Global Navigation Satellite System (GNSS)-based positioning and timing for intelligent transportation systems. These networks also provide continuous observations that can support regional GNSS integrity monitoring. This study develops and demonstrates a framework that treats a statewide CORS network as a spatially distr…

詳細を見る →

astro-ph.SR2026年8月10日

Synthetic Fe XIII 1074.7 nm Observations of Torsional Alfvén Waves in Coronal Waveguides

Samuel Skirvin, Richard Morton, Thomas Schad

Torsional Alfvén waves are a promising mechanism for transporting energy through the solar atmosphere, with implications for coronal heating and solar wind acceleration. Recently, signatures of torsional Alfvén waves have been observed with the Daniel K. Inouye Solar Telescope. We aim to investigate the effects of line of sight integration and plasma conditions on the observable properties of the torsional mode. Here we present three-dimensional magnetohydrodynamic simulations of multiple corona…

詳細を見る →

astro-ph.IM2026年8月10日

A Hybrid R-Theta Fiber Positioning Robot Using a Piezoelectric Bender for Radial Motion

Michael Schubnell, Tim Fanning, Andrew Hope, Joseph Silber, Greg Tarlé, Nicholas Wenner

Future massively multiplexed spectroscopic surveys require focal planes with increasingly dense arrays of robotic fiber positioners. The DESI (Dark Energy Spectroscopic Instrument) fiber positioners, based on a two-axis Theta-Phi motorized architecture, have demonstrated excellent reliability and performance during operations and provide the benchmark for evaluating new concepts. However, proposed next-generation instruments such as Spec-S5 require a substantially smaller positioner pitch than D…

詳細を見る →

astro-ph.HE2026年8月10日

Timing and statistical analysis of single-pulse search pulsar discoveries from the PALFA survey

Graham M. Doskoch, Maura A. McLaughlin, B. Allen, A. Brazier, F. Camilo, F. Cardoso, S. Chatterjee, J. M. Cordes et al.

Almost two decades after their discovery, pulsars discoverable only through their single, dispersed radio pulses, known as rotating radio transients (RRATS), remain a poorly-understood class of objects. Compared to the overall pulsar population, few have timing solutions, limiting our ability to understand the mechanisms underlying their sporadic emission. Here, we present a single-pulse analysis of twelve sources from the PALFA survey, consisting of eleven objects initially identified as RRATs…

詳細を見る →

astro-ph.HE2026年8月9日

Simulation-based inference for AGN jet population modelling: Towards more robust comparisons of black hole jet speeds

Clara Lilje, James H. Matthews, Rob Fender

We present the most complete modelling of the MOJAVE 1.5 Jansky Quarter Century active galactic nuclei (AGN) jet population, using likelihood-free simulation-based inference. Due to the complex impact of a flux-limit on observed AGN data sets, careful modelling of the parent population is required. In particular, when observing and fitting to multiple data distributions likelihoods become non-intuitive. Parameter degeneracies further complicate the problem and make it suitable for likelihood-fre…

詳細を見る →

astro-ph.IM2026年8月9日

The James Webb Space Telescope Absolute Flux Calibration. VI. Near-Infrared Camera Imaging and Coronagraphy

Martha L. Boyer, Benjamin Sunnquist, Bryan Hilbert, Dan Coe, Varun Bajaj, Paul Bennet, Julien Girard

We present an updated flux calibration for all imaging modes of the Near-Infrared Camera on JWST that converts instrumental units to physical surface brightness units of MJy sr^-1. This calibration includes observations of 19 flux standard stars spanning 3.5 years, with a mix of A dwarfs, solar analogs, and hot stars. All 5 coronagraphic setups, all 29 filters, and both weak lenses are calibrated. This is the first on-sky calibration for the weak lenses used in Time Series observations and for s…

詳細を見る →

astro-ph.IMastro-ph.CO2026年8月9日

QUIJOTE scientific results - XX. Commissioning and First Results from the Thirty and Forty Gigahertz Instrument (TFGI)

M. Fernández-Torreiro, J. A. Rubiño-Martín, R. T. Génova-Santos, G. Pascual-Cisneros, A. Fasano, F. J. Casas, R. J. Hoyland, M. W. Peel et al.

We present the commissioning and first results of the Thirty and Forty Gigahertz Instrument (TFGI), which observes the sky at 31 and 41 GHz with angular resolutions of 21' and 18' from the second QUIJOTE telescope at the Teide Observatory. Its primary goal is to conduct a deep cosmological survey in selected regions of the Northern sky with high-sensitivity polarization measurements. The commissioning phase covered Nov2021-Oct2022, during which the instrument operated with a configuration of 7 r…

詳細を見る →

astro-ph.SR2026年8月9日

Sun-to-Earth Coronal Mass Ejection Simulations From a Vector Magnetogram

Yifu An, Gábor Tóth, Beatrice Popescu Braileanu

We implement a novel approach to performing Sun-to-Earth coronal mass ejection (CME) simulations and test it on three geo-effective space weather events. Using a vector magnetogram observed prior to the CME as the boundary condition, we reconstruct non-linear force free field (NLFFF) solutions in solar active regions with an established magneto-frictional method. We find a pre-eruption solar corona containing the NLFFF in the AWSoM model, which then spontaneously erupts. We apply STITCH, a photo…

詳細を見る →

astro-ph.GAastro-ph.IMastro-ph.SR2026年8月9日

Exploration of UV-bright sources in Globular cluster NGC 3201 using UVIT observations

Manasi Kulkarni, Sonika Piridi, Ranjan Kumar, Ananta C. Pradhan

We present a comprehensive study of the ultraviolet (UV)-bright stellar population in the globular cluster NGC 3201 using the Ultraviolet Imaging Telescope (UVIT) onboard AstroSat. By combining far-UV photometry of the UVIT F148W and F169M filters with Gaia and ground-based telescope optical data, we construct UV$-$optical color-magnitude diagrams (CMDs) to identify UV-bright stellar evolutionary phases. Physical parameters of all detected sources are derived by fitting stellar atmosphere models…

詳細を見る →

astro-ph.SR2026年8月9日

Coronal Rain Driven by Low-Frequency Impulsive Heating: Dependence of Dynamics and Morphology on Coronal Heating and Magnetic Field

Takero Yoshihisa, Takaaki Yokoyama

We performed numerical simulations to investigate how coronal heating and magnetic field strength regulate the dynamics and morphology of coronal rain in the solar corona. Coronal rain is widely interpreted as a manifestation of thermal non-equilibrium and thermal instability. Many previous studies have investigated condensation under (quasi-)steady heating scenarios, but such heating models do not fully explain the observed properties, including multiple clumps and symmetric drainage toward bot…

詳細を見る →

astro-ph.HE2026年8月9日

Slow Cosmic-Ray Diffusion in Supersonic and Super-Alfvénic Turbulence

Yue Hu

Extended TeV-PeV gamma-ray halo observations imply cosmic-ray (CR) diffusion that is both substantially slower than the Galactic mean and only weakly anisotropic, despite the presence of a large-scale Galactic magnetic field. We investigate whether such transport can arise in partially ionized source environments, where ion-neutral damping removes the small-scale fluctuations responsible for gyroresonant scattering. Using two-fluid magnetohydrodynamic turbulence simulations with relativistic tes…

詳細を見る →

astro-ph.HEphysics.plasm-ph2026年8月9日

Plasmoid-Mediated 2D Magnetic Reconnection in Partially Ionized Plasmas

Yue Hu, Siyao Xu, Grzegorz Kowal, James M. Stone, Alex Lazarian, Hui Li

Magnetic reconnection in partially ionized plasmas is an important channel for energy release. While the plasmoid instability is well characterized in 2D fully ionized plasmas, its behavior in the presence of neutral-dominated plasma remains poorly understood in the nonlinear, high-Lundquist-number ($S = 10^5$) regime. We present high-resolution ($16384 \times 4096$ cells) two-dimensional two-fluid (ion $+$ neutral) simulations of Harris-sheet reconnection with upstream plasma beta $β= 2$, compa…

詳細を見る →

astro-ph.SRastro-ph.IMphysics.comp-ph2026年8月9日

FORTVSH: A Fortran Module For Vector Spherical Harmonics Computations

Justin G. Elfritz

The vector spherical harmonics (VSH) are crucial ingredients for representation of arbitrary vector fields in curvilinear coordinate systems throughout mathematical physics. Performant, efficient computations of the VSH are essential to high-performance computing applications that utilize spectral analysis, including magnetohydrodynamics (MHD) simulations for geophysics and astrophysics. The open-source FORTVSH package provides a catalog of numerical routines for evaluating various VSH forms and…

詳細を見る →

astro-ph.HE2026年8月9日

Three-Dimensional Expansion of Iron Ejecta in Cassiopeia A with Chandra and XRISM

Aya Bamba, Tomoki Kadoya, Kouichi Hagino, Jacco Vink, Manan Agarwal, Masahiro Ichihashi, Paul Plucinsky

Measurement of the expansion structure of ejecta in supernova remnants (SNRs) provides important information about their explosion mechanism. We combine Chandra proper-motion measurements with XRISM Doppler measurements to derive an approximate, region-averaged three-dimensional velocity map of the Fe-K-emitting ejecta in Cassiopeia A (Cas A), one of the youngest Galactic core-collapse SNRs. Proper motions were measured using the optical flow method. We find that the Fe-K-emitting ejecta expand…

詳細を見る →

astro-ph.GAastro-ph.IM2026年8月9日

A Catalog of Giant Radio Source Candidates from TGSS ADR1 Using a Deep Learning--based Pipeline

Baoqiang Lao, Binghua Liang, Shaoguang Guo, Junxiu Liu, Xiaolong Yang, Rushuang Zhao, Yang Kun

We present a catalog of 5,595 giant radio source (GRS) candidates, defined by a largest (projected) linear size (LLS) exceeding 0.7 Mpc. Of these, 4,566 would be new discoveries if confirmed. These candidates were identified through a systematic and automated search of the first Alternative Data Release of the TIFR GMRT Sky Survey (TGSS ADR1) using a deep learning--based pipeline that incorporates a radio sources detection model and the likelihood ratio method. Across the full sample, the LLS re…

詳細を見る →

cs.AIastro-ph.IM2026年8月9日

Estimating Uncertainty in Galaxy Morphology Classification

Kai Cheng, Ruoqi Wang, Qiong Luo

Astronomers classify galaxy morphology to investigate cosmic evolution. While deep foundation models are increasingly utilized in Galaxy Morphology Classification (GMC), little work has been done on evaluating the uncertainty of GMC results. Uncertainty evaluation is important because astronomical data are inherently noisy due to instrumental and environmental limitations. Also, the continuous evolution of galaxies creates intrinsic morphological ambiguity. However, current foundation models ope…

詳細を見る →

astro-ph.GA2026年8月9日

Constructing a Hydrogen Line Library for Lyα Emitters at Low Redshifts (z < 0.4): Estimating Dust Extinction and Assessing Paschen line Detectability with SPHEREx

Junho Song, Hyunmi Song, Hyunjin Shim

Hydrogen recombination lines, one of the strongest emission lines from star-forming galaxies, are used to probe the early Universe as indicators of star formation rates and ionizing photon production rates. Ratios between different recombination lines provide clues to estimate dust attenuation, in addition to the H II region physical diagnostics. To prepare for future near-infrared spectral surveys and optical narrow-band imaging surveys aiming for hydrogen lines in different redshifts, we const…

詳細を見る →

astro-ph.GAastro-ph.HE2026年8月9日

The ALMA carbon monoxide supernova (ACOS) survey II. Turbulent giant molecular clouds at the positions of core-collapse supernovae

M. Solar, M. J. Michałowski, J. Nadolny, J. Sollerman, E. Zapartas, A. Oliva, L. Galbany, J. Hjorth et al.

Context. Study of cold molecular hydrogen gas (hereafter molecular gas) provides crucial insights into its interplay with star-forming regions. However, the connection between molecular gas turbulence and the sites of massive star ($> 8~\rm{M}_{\odot}$) explosions as core-collapse supernovae (CCSNe) remains unexplored. Aims. We measure for the first time the turbulence of molecular gas in environments of CCSNe, with the aim to constrain the nature of their progenitors. Methods. In order to reach…

詳細を見る →

astro-ph.GA2026年8月9日

GATOS: Distinct Feedback Modes in AGN Central Regions Revealed by Spatially Resolved JWST Spectroscopy

Lulu Zhang, Chris Packham, Erin K. S. Hicks, Ismael García-Bernete, Almudena Alonso-Herrero, Ric I. Davies, Martin J. Ward, Daniel E. Delaney et al.

This manuscript presents JWST MIRI/MRS observations of the central $r \approx 40-240$ pc regions of five active galactic nuclei (AGN) spanning a wide range of luminosities (${\rm log}\,L_{\rm bol}/{\rm erg\,s^{-1}} \approx 39.8-43.8$). Combining multiphase diagnostics from polycyclic aromatic hydrocarbons (PAHs), molecular hydrogen (H$_2$), and ionized gas at spatial scales of $\sim 4-24$ pc, this study presents a spatially resolved investigation into the effects of the two distinct AGN feedback…

詳細を見る →

physics.plasm-phastro-ph.EPphysics.comp-ph2026年8月9日

Dipole-Field Magnetic Windows for Radio-Frequency Transmission Through Hypersonic Plasma Sheaths: A Reduced-Order Scaling Model

Richard Lieu

Hypersonic vehicles and atmospheric-entry bodies can experience radio-frequency communication blackout when shock-heated gas surrounding the vehicle becomes sufficiently ionized that plasma cutoff and collisional attenuation restrict electromagnetic transmission. Magnetic-window approaches attempt to reduce this loss by exploiting the anisotropic dispersion of a magnetized plasma, in which selected right-hand or whistler-like modes may propagate along preferred directions. This paper develops a…

詳細を見る →

math.APastro-ph.SRphysics.flu-dyn2026年8月9日

On the nonlinear instability of nonrotating Stars

Zhiwu Lin, Xinlin Wu

We study radial nonlinear instability of compactly supported nonrotating equilibria of the three-dimensional Euler--Poisson system with a physical-vacuum boundary. Let $n^u(μ)$ denote the radial instability index furnished by the turning-point theory of Lin and Zeng. Under general structural assumptions on the pressure law, suppose that $n^u(μ)>0$ and that the equilibrium is not a mass extremum, $M'(μ)\neq0$. Conditional on the existence of a sufficiently regular radial solution on the relevant…

詳細を見る →

astro-ph.GA2026年8月9日

KCWI Discovery of a Spatially Resolved Kpc-Scale Ionized Outflow in NGC 1275

Kylie Yui Dan, Hanae Inami, Thomas Bohn, Sylvain Veilleux, Vivian U, Tianmu Gao, Justin Kader, Rosalie McGurk et al.

We present new Keck Cosmic Web Imager observations of the central few kiloparsecs of NGC 1275, the brightest cluster galaxy of the Perseus Cluster. These integral field spectroscopic data reveal a warm-ionized outflow traced by H$β$ and the [O III] doublet extending out to $\sim2.5$ kpc from the nucleus. The warm-ionized outflow has an [O III]-derived $v_{50}$ of up to $\sim570$ km/s, $w_{80}$ of up to $3780$ km/s, and H$β$-derived outflowing mass of $(2.7 \pm 0.3)\times 10^6$ M$_\odot$. Our H$β…

詳細を見る →

astro-ph.IM2026年8月9日

Multi-night photometric repeatability of STDWeb: an empirical error budget from a 14-night campaign on a single field

Pierre-Yves Lechapelain

Web-based photometric pipelines such as STDWeb are routinely used by small observatories and professional-amateur networks across the full range of photometric science: variable stars, supernovae, exoplanet transits, transient follow-up. The formal magnitude uncertainty they report describes a single reduction of a single frame; campaign science instead requires the scatter of the same star, same field, night after night. We measure this empirically on the field of the Einstein Probe trigger EP-…

詳細を見る →

astro-ph.IM2026年8月9日

Design and simulation of a photonic lantern-inspired astrophotonic chip for spectral sensing

Avi Patel, Kevin A. Bundy, Aditya Sengupta, Matthew C. DeMartino, Anna Gagnebin, Emiel Por, Majid Mohammad, Michael Arena et al.

Compact astrophotonic sensors can trade general-purpose spectral coverage for task-specific wavelength discrimination in a small integrated footprint. Developed with the Mazin Lab at UC Santa Barbara, this chip couples a single-mode input into a multimode interference region and seven-port fanout, producing wavelength-dependent output power fingerprints for spectral retrieval. Using ANSYS Lumerical FDTD simulations in silicon nitride, we compare symmetric and staggered-release geometries and qua…

詳細を見る →

astro-ph.IM2026年8月9日

Design evolution for the Wide-field Spectroscopic Telescope

Will Saunders, Corentin Cudennec, Roland Bacon, Philippe Dierickx, Roelof de Jong, David Lee, Gaston Gausachs

WST is proposed as the next large ESO project to follow ELT, combining Multi-Object Spectroscopy and Integral Field Spectroscopy. Each mode offers order-of-magnitude gains over current systems, and each also presents unprecedented design challenges, both separately and in combination. For large MOS systems, both science performance and spectrograph costs vary steeply with the delivered image quality, so exceptional delivered image quality is paramount. But the 12m aperture and 2 degree field giv…

詳細を見る →

astro-ph.GA2026年8月9日

The Quasar Feedback Survey: Ionised Outflows in type 2 QSOs with MUSE data

M. Bianchin, C. M. Harrison, T. Costa, V. Mainieri, R. A. Riffel, G. Venturi, D. Kakkad, C. Ramos Almeida et al.

We study ionised gas properties in a sample of 18 luminous (log L$_{\rm bol}\geq45$ erg/s) obscured QSOs at 0.085<z<0.2 observed with VLT/MUSE as part of the multi-wavelength Quasar Feedback Survey (QFeedS) and with VLA at low- and high-resolution data. We compare the outflow-related quantities with values reported in the literature and investigate possible correlations between the outflows and other properties of the ionised gas such as the electron density. We adopt a non-parametric approach t…

詳細を見る →

astro-ph.SRastro-ph.HE2026年8月9日

From Light to Sound: Spectroscopic Evolution & Sonification of the flaring Nova V612 Scuti

Pragati Acharya, Elias Aydi, Kirill V. Sokolovsky, Brian D. Metzger, Laura Chomiuk, Peter Craig, Luca Izzo, Justin D. Linford et al.

We present photometric and spectroscopic observations of the 2017 Galactic nova V612 Sct, whose optical evolution was marked by multiple unusually large maxima. The eruption included two prominent flares lasting around a month each and reaching amplitudes of about 2.5 mag, followed by a series of smaller flares. Extensive spectroscopic monitoring reveals a striking pattern: with each flare, new absorption systems emerge at progressively higher velocities. This behavior, also seen in other flarin…

詳細を見る →

astro-ph.HE2026年8月9日

On the Physical Origins of Long Period Radio Transients

Yuanhong Qu, Bing Zhang

Long-period radio transients (LPRTs) are a rapidly growing class of coherent radio sources with periods ranging from minutes to hours, whose central engines and emission mechanisms remain unclear. Motivated by the detection of red dwarf (RD) companions in several LPRTs and by generic period constraints from the Roche limit and the mass transfer limit, we argue that LPRTs naturally separate into two broad classes: shorter-period sources that are likely isolated compact objects and longer-period s…

詳細を見る →

astro-ph.GA2026年8月9日

Kings of the Milky Way: A Homogeneous Gaia DR3 Analysis of King Open Clusters and the Galactic Disc Metallicity Gradient

Talar Yontan, Selçuk Bilir, Hikmet Çakmak, Olcay Plevne, Esin Soydugan, Seval Taşdemir, Remziye Canbay, Deniz Cennet Çınar et al.

This study aims to establish an internally homogeneous set of structural, astrophysical, and kinematical parameters for King open clusters and to assess their role as tracers of the Galactic thin disc. We present a homogeneous structural, astrophysical, and kinematical analysis of 27 King open clusters using high-precision Gaia DR3 astrometry, photometry, and spectroscopy. Cluster reddenings, distances, metallicities, and ages are determined via a homogeneous Markov Chain Monte Carlo isochrone-f…

詳細を見る →