研究動向

astro-ph.SRastro-ph.HE2026年9月6日

IPHAS J190812.63+045728.1: A deeply eclipsing, X-ray bright cataclysmic variable with frequent outbursts

Raimundo Lopes de Oliveira, Albert Bruch, Koji Mukai, A. S. de Araujo, Guilherme P. Guimarães, Ted Leandro de Almeida

We present a multi-wavelength characterization of IPHAS J190812.63+045728.1. Independently discovered by us after being serendipitously observed by XMM-Newton, followed up with optical photometry with SPARC4/OPD and spectroscopy with GMOS/Gemini South, and exploring archival TESS and ZTF observations, we reveal the system to be an eclipsing accreting white dwarf (WD) system with an orbital period of 5.073 h. The deep optical and flat-bottomed X-ray eclipses completely occult the WD and the accre…

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astro-ph.SR2026年9月6日

Coordinated Coronagraphic Observations from Proba-3 and Aditya-L1: Investigating CME Energetics in the Inner Corona

Anjali Agarwal, Wageesh Mishra, R. Ramesh, V. Muthu Priyal, A. N. Zhukov, Jagdev Singh, Nat Gopalswamy, Soumyaranjan Khuntia et al.

Constraining the plasma properties and energetics of coronal mass ejections (CMEs) in the inner corona is essential for understanding their early evolution, yet remains challenging because of limited observations. We investigate the mass and density evolution, and energy partitioning of two CMEs observed on 2025 September 14 and 16, and assess the potential of coordinated Proba-3/ASPIICS and Aditya-L1/VELC observations to constrain CME energetics in the low corona. We present the first coordinat…

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astro-ph.GAcs.CVcs.LG2026年9月6日

Deep learning from the crowd Fundamentals of morphological galaxy classification

Luis Enrique Sucar, Carlos del Burgo, Jonathan Serrano-Pérez

Aims. The objective of this work is to adapt a deep neural network model to perform galaxy morphological classification trained from crowd annotations, considering the training scheme, the agreement between the annotators, and the hierarchy. Methods. We use Galaxy Zoo 1 as our experimental testbed and trained a convolutional neural network (CNN) for the automatic classification of galaxies' morphologies. We analyze the impact of the following aspects on the classification accuracy and training e…

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astro-ph.GAastro-ph.SR2026年9月6日

Interstellar Complex Organic Molecules and Molecular Outflows in NGC 1333 IRAS 4B and 4B' Observed Using NOEMA

C. C. Sarver, M. M. Giese, D. C. Lis, S. L. Widicus Weaver

We present interferometric observations with the Northern Extended Millimeter Array (NOEMA) of NGC 1333 IRAS 4B and 4B', two young stellar objects (YSOs) within the Perseus molecular cloud. YSOs, especially Class 0 protostars, are rich in gas-phase interstellar complex organic molecules (iCOMs), but relatively little is known about the spatial distribution of these important prebiotic molecules. Various molecules were imaged within IRAS 4B and the surrounding area in the 145 GHz spectral range,…

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astro-ph.GAastro-ph.SR2026年9月6日

Interstellar Complex Organic Molecules and Molecular Outflows in NGC 1333 IRAS 4B and 4B' Observed Using NOEMA

C. C. Sarver, M. M. Giese, D. C. Lis, S. L. Widicus Weaver

We present interferometric observations with the Northern Extended Millimeter Array (NOEMA) of NGC 1333 IRAS 4B and 4B', two young stellar objects (YSOs) within the Perseus molecular cloud. YSOs, especially Class 0 protostars, are rich in gas-phase interstellar complex organic molecules (iCOMs), but relatively little is known about the spatial distribution of these important prebiotic molecules. Various molecules were imaged within IRAS 4B and the surrounding area in the 145 GHz spectral range,…

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astro-ph.GAastro-ph.HE2026年9月6日

Connecting the little dots in polarized light

Piero Madau, Roberto Maiolino, Francesco D'Eugenio

Recent observations of the local Little Red Dot (LRD) analog SDSS~J1025+1402 have revealed that the optical continuum is polarized at the ~1.5% level, while broad Halpha has lower polarization (~0.7%) and a different polarization angle. We explain these properties in a scenario in which LRDs are dust-obscured Little Blue Dots (LBDs) viewed at high inclination and powered by super-Eddington accretion. In this framework, electron scattering in the geometrically thick inner accretion flow produces…

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gr-qcastro-ph.IM2026年9月6日

Alternative neural-network follow-up for all-sky FrequencyHough in continuous gravitational-wave searches

Martina Di Cesare, Pia Astone, Rosario De Rosa, David Keitel, Cristiano Palomba, Marco Serra

Continuous gravitational waves are long-lived signals emitted by spinning neutron stars (NSs) or boson clouds around black holes. While the Milky Way is expected to host $\mathrm{O}(10^{8}-10^{9})$ NSs, only $\mathrm{O}(10^{3})$ are currently identified through electromagnetic observations. This large observational gap motivates searches based on alternative messengers. In particular, all-sky searches for continuous gravitational waves (GWs) offer a unique opportunity to detect NSs that are elec…

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astro-ph.HEastro-ph.SR2026年9月6日

The First Multi-Messenger Nova: External Shocks, TeV Photons, and Neutrinos in the Next Eruption of T CrB

E. Aydi, P. Craig, K. V. Sokolovsky, L. Chomiuk, C. C. Cheung, L. Izzo, J. D. Linford, B. D. Metzger et al.

T Coronae Borealis is the most compelling anticipated Galactic recurrent nova and one of the best opportunities to test whether nova eruptions can become genuine multi-messenger transients. Recent observational work on classical novae has shown that the GeV $γ$-ray luminosity correlates strongly with the differential velocity between interacting outflows, suggesting that shock power depends strongly on velocity contrast. We apply this empirical framework to T CrB and compare it with the 2021 eru…

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physics.pop-phastro-ph.IMphysics.opticsphysics.space-ph2026年9月6日

Project Setu: 3D Multi-Physics Design and Spaceflight-Validated Framework for a 0.20c Relativistic Lightsail

Prashant Suresh Kamble

Deep-space exploration beyond the solar system requires eliminating chemical propellant mass penalties to achieve relativistic flight velocities (0.166c at 180 s, reaching the mission target of 0.20c at 227 s). This study presents a 3D multi-physics numerical framework for a 4.0-meter circular lightsail propelled by a 100 GW ground laser array, coupling 3D Maxwell FDTD wave optics, non-linear membrane mechanics, and Stefan-Boltzmann thermal radiation in ANSYS Mechanical APDL and Ansys Lumerical.…

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physics.pop-phastro-ph.IMphysics.opticsphysics.space-ph2026年9月6日

Project Setu: 3D Multi-Physics Design and Scaled Structural Analysis for a Relativistic Lightsail Architecture

Prashant Suresh Kamble

Deep-space exploration beyond the solar system requires eliminating chemical propellant mass penalties to achieve relativistic flight velocities (0.166c at 180 s, reaching the mission target of 0.20c at 227 s). This study presents a 3D multi-physics numerical framework for a 4.0-meter circular lightsail propelled by a 100 GW ground laser array, coupling 3D Maxwell FDTD wave optics, non-linear membrane mechanics, and Stefan-Boltzmann thermal radiation in ANSYS Mechanical APDL and Ansys Lumerical.…

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astro-ph.HEgr-qc2026年9月6日

An HLLD Implementation for General Relativistic Magnetohydrodynamics in AthenaK

Jacob Fields, George N. Wong, James M. Stone

We present an implementation of an HLLD approximate Riemann solver for the AthenaK astrophysics code with support for full general relativistic magnetohydrodynamics via a tetrad frame transformation. Our implementation uses an initial guess for the HLLD iterative solve which eliminates the need for an additional conserved-to-primitive inversion, which greatly accelerates performance without affecting accuracy. Additionally, by coupling the method with a first-order flux correction, we are able t…

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astro-ph.EPastro-ph.GA2026年9月5日

Shaving the Outskirts of Planetary Systems Probed by Roman via Stellar Flybys

Donald Liveoak, Tim Hallatt, Sarah Millholland

The recently launched Nancy Grace Roman Space Telescope (\textit{Roman}) will soon begin observations that promise to revolutionize our understanding of exoplanet demographics. \textit{Roman}'s Galactic Bulge Time-Domain Survey (GBTDS) will observe the Galactic Bulge via transit and microlensing techniques, providing a unique opportunity to study hot Jupiters as well as long-period/free-floating exoplanets in a dense and kinematically hot stellar environment. In this Letter, we quantify how repe…

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astro-ph.GA2026年9月5日

FAST Observations of Filamentary and Compact H I Structure in a Magellanic Stream IV Field

Yuxin Xiao, Qingzheng Yu, Taotao Fang, Di Li, Shulan Yan, Shuo Zhang

The Magellanic Stream (MS) is believed to have formed from gas removed from the Large and Small Magellanic Clouds through tidal forces and hydrodynamic interactions with the Milky Way's gaseous halo. It provides an important laboratory for studying how stripped gas fragments, mixes, and evolves in a circumgalactic environment. In this work, we present HI observations of a $3.8^\circ\times2.2^\circ$ field in the MS IV region, using the data from the Commensal Radio Astronomy FasT Survey (CRAFTS).…

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astro-ph.HEgr-qc2026年9月5日

The accuracy of merger times in hierarchical black hole triples

Giulia Fumagalli, Alejandro Vigna-Gómez

Orbit-averaged equations are widely used to model the gravitational-wave-driven evolution of compact binaries. Their validity relies on the radiation-reaction timescale being much longer than the orbital period, an assumption that can break down for highly eccentric systems. In this work, we investigate the impact of orbit averaging on merger-time estimates by comparing orbit-averaged and non-orbit-averaged prescriptions. We apply our analysis to two different astrophysically motivated populatio…

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gr-qcastro-ph.HE2026年9月5日

Physics-based phenomenological modeling of binary black hole hierarchical formation 1: Synthetic universes from globular cluster simulations for GWTC

R. O'Shaughnessy, R. Mechum, M. Qazalbash, Z. Rosenberg, M. Zeeshan

We iteratively model the GWTC-5.0 binary-black-hole census with three components. First, a physically normalized population from Rapster globular-cluster simulations spans cluster mass, metallicity, formation redshift, compactness, and natal black-hole spin. Hierarchical mergers reproduce higher-mass events and their larger effective-spin dispersion, provided black holes are born with zero natal spin. Second, a phenomenological field (isolated-binary) channel supplies the low-mass, preferentiall…

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gr-qcastro-ph.GAastro-ph.IMhep-ph2026年9月5日

Self-supervised reconstruction of transients in data from space-borne gravitational-wave detectors

Yuxiang Xu, Minghui Du, Bo Liang, Zihao Xiao, Tianyu Zhao, Peng Xu

Space-based gravitational-wave (GW) data may contain transient signals whose waveform morphologies are not known in advance. Extracting these signals is important for characterizing new sources and mitigating instrumental anomalies. However, existing deep neural network (DNN)-based extraction approaches rely on clean training targets and waveform-class-specific examples, which may limit their applicability when the transient morphology is not specified in advance. This work develops a Noise2Nois…

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astro-ph.SRastro-ph.HE2026年9月5日

Magnetically Confined Mountains on Accreting White Dwarfs

Pedro H. B. Rossetto, Manoel F. Sousa, Diego A. Falceta-Gonçalves

The hydromagnetic structure of magnetically confined mountains on accreting white dwarfs is computed, alongside the effects of accretion on the reduction of the star's magnetic field. The equilibrium structure of the mountain is obtained by numerically solving the Grad-Shafranov equation with a self-consistent scheme that enforces magnetic flux freezing. For characteristic system parameters, it is shown that magnetic field lines are significantly deformed and dragged equatorwards by mountains wi…

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astro-ph.SRastro-ph.GA2026年9月5日

A Uniform Census of Variable Stars in M101 Based on HST/ACS Photometry

Jiyu Wang, Xiaodian Chen, Pinjian Chen, Jianxing Zhang, Shu Wang, Licai Deng

We present a homogeneous HST/ACS F555W/F814W time-series census of variable stars in two M101 disk fields, using a uniform multi-band reduction and reproducible variable-selection workflow for nearby SN-host galaxies. Supplementary archival F555W epochs are used only to refine selected long-period solutions. Candidates are selected with Lomb-Scargle period searches, Fourier light-curve modeling, two-band consistency statistics, artificial-star-test photometric corrections, and mode-aware Cepheid…

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eess.SPphysics.space-ph2026年9月5日

Wideband HF Skywave Propagation: A Review with Link Modeling Corroborated by Propagation Data

Eric Weber, Ted Nowak, Joseph Berg, Nader Behdad

The high-frequency (HF) band, ranging from 3 to 30 MHz, is widely used in a number of applications such as beyond-line-of-sight (BLOS) communications and over-the-horizon radar systems. The long-range propagation characteristics of the HF band rely on the Earth's ionosphere as a refracting medium to establish BLOS wireless links. However, traditional HF communications links often use channels with narrow bandwidths (typically 3 kHz), which limits the amount of data that can be transmitted. In th…

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nucl-thastro-ph.HE2026年9月5日

Hadron resonance gas with density-dependent interactions for neutron stars and heavy-ion collisions

Volodymyr Vovchenko, Volodymyr Kuznietsov, Tripp Moss

We present a density-dependent generalization of the van der Waals hadron resonance gas model (DD-HRG) for describing both the hot hadronic matter created in heavy-ion collisions and the cold, dense matter inside neutron stars. Non-resonant interactions are incorporated through a generalized excluded-volume prescription with a density-dependent available-volume fraction, supplemented by an arbitrary density-dependent mean field. With isospin-dependent interaction parameters constrained by empiri…

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astro-ph.HE2026年9月5日

A Possible X-ray and Gamma-ray Quasi-Periodic Oscillation in GRB 241030A

Noel Klingler, Cecilia Chirenti, M. Coleman Miller, Amy Lien, Simone Dichiara

Quasiperiodic oscillations (QPOs) in gamma-ray intensity have been reported from a few gamma-ray bursts. These QPOs could be related to fundamental frequencies in the sources, which would lead to new insights about these systems. Here we report on our analysis of GRB~241030A, a several-minute-long burst with $\sim 10$ gamma-ray flares that have approximate periodicities at f ~ 0.04 Hz and f ~ 0.08 Hz. This quasi-periodicity is seen in X-rays with the Swift X-Ray Telescope (XRT) as well as in gam…

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astro-ph.SRastro-ph.GA2026年9月5日

Unresolved triple systems in the aged open cluster Trumpler 19: Discovery, confirmation, and implications

D. Minniti, R. K. Saito, V. D. Ivanov, C. O. Obasi, P. W. Lucas, J. G. Fernández-Trincado, J. Alonso-García, E. R. Garro et al.

It is difficult to identify unresolved triple and higher-order systems beyond the solar vicinity. Star clusters yield controlled environments with known physical parameters, providing a way to explore homogeneous stellar samples. Combining modern optical and near-IR surveys, our main goal is to explore the region of the color-magnitude diagrams located above the sequence of equal-mass binaries, which is inhabited by unresolved triple and quadruple systems. Specifically, here we aim to discover a…

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astro-ph.GA2026年9月5日

Tracing the Hidden Molecular Gas in the Small Magellanic Cloud with SOFIA and APEX

K. Rodriguez-Ambler, R. Herrera-Camus, M. Rúbio, A. D. Bolatto, D. Riquelme-Vásquez, K. Jameson, C. Muñoz-López, E. J. Tarantino et al.

In low-metallicity environments, reduced dust abundance weakens molecular cloud shielding against far-ultraviolet radiation, enhancing CO photodissociation and producing extended CO-faint or CO-dark molecular gas. The [CII] 158 $μ$m line is a key tracer of these CO-faint phases. We characterize the multiphase origin of [CII] emission and quantify the CO-faint molecular gas fraction across several regions of the Small Magellanic Cloud (SMC), the nearest low-metallicity ($\sim 0.2 Z_\odot$) galaxy…

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astro-ph.GA2026年9月5日

Reigniting the FUSE I: Star Formation in Massive Elliptical Galaxies

Michael Reefe, Michael McDonald, Eric Miller, Thomas Brown

In this inaugural paper of our "Reigniting the FUSE" series, we present the data collection & reduction, methodology, and preliminary results for a comprehensive and homogeneous reanalysis of all 30 massive elliptical galaxies that have archival far-ultraviolet (FUV) spectra with the Far Ultraviolet Spectroscopic Explorer (FUSE). We perform SED fitting to these spectra, with aperture-matched photometry from GALEX, SDSS, DES/DECaLS, 2MASS, and WISE, and construct a catalogue of high quality const…

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gr-qcastro-ph.HEhep-th2026年9月5日

Effective Field Theory of Gravity in Relativistic Media

Beka Modrekiladze

We develop an effective field theory of gravity in relativistic media. Integrating out the medium leaves vacuum gravity with updated Feynman rules: a graviton propagator dressed by the stress-energy two-point function of the environment, medium-induced bulk graviton vertices from higher correlators, and generalized worldline couplings encoded in matched Wilson coefficients. The diagram topologies are unchanged from vacuum, so different media (perfect fluids, collisionless matter, coherent scalar…

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astro-ph.SRastro-ph.GAastro-ph.IM2026年9月5日

Calibration of the Next Generation Palomar Spectrograph as a Stellar Speedometer

Pranav Nagarajan, Kareem El-Badry

We calibrate the Next Generation Palomar Spectrograph (NGPS) for precision stellar radial-velocity (RV) measurements using repeated observations of 24 Gaia-ESO RV standards spanning $G=11$-$18$. Because NGPS is mounted at the Hale telescope's Cassegrain focus, changes in instrumental flexure produce wavelength-solution shifts of tens of km s$^{-1}$, with substantial time and wavelength dependence. We develop a pipeline that measures these shifts directly from each science exposure, using telluri…

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astro-ph.HEastro-ph.GA2026年9月5日

Rapid radio variability in the $z\sim7$ blazar VLASS J0410$-$0139: Indication of a hidden population of weak radio jets at Cosmic Dawn

Silvia Belladitta, Eduardo Bañados, Anniek J. Gloudemans, Timothy W. Shimwell, Emmanuel Momjian, Huib Intema, Chiara Mazzucchelli, Christian Fendt et al.

Doppler boosting allows blazars to be detected out to high-$z$, making them promising probes of the intergalactic medium through the 21 cm forest. We report 0.144$-$11 GHz observations of the most distant known blazar, VLASS J041009.05$-$013919.88 at z$\sim$7, obtained with the upgraded Giant Metrewave Radio Telescope (uGMRT), the LOw Frequency ARray (LOFAR) and the Very Large Array (VLA). The first uGMRT epoch (300$-$820 MHz, April 2023) revealed an inverted radio spectrum which, combined with…

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astro-ph.GA2026年9月5日

LOFAR radio properties of quasars hosting Extremely High Velocity Outflows

Amy L. Rankine, Paola Rodríguez Hidalgo

Quasar winds are a potential contributor to the radio emission observed in the so-called 'radio-quiet' quasars. Extremely High Velocity Outflows (EHVOs), with bulk velocities >0.1c, represent some of the most energetic of these winds. In this work, we investigate the radio properties of quasars hosting EHVOs in order to assess whether such high-velocity winds contribute to the observed radio emission. We cross-match the catalogue of EHVOs from the Sloan Digital Sky Survey with the high-sensitivi…

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astro-ph.SRastro-ph.EPastro-ph.GA2026年9月5日

Deep H$α$ Imaging Survey of IC 348 with the Hubble Space Telescope: I. Accretion Properties of Stellar and Substellar Objects

Lillian Yushu Jiang, Brendan P. Bowler, Yifan Zhou, Adam L. Kraus, Sean M. Andrews, Lynne A. Hillenbrand, Michael J. Ireland, Zhaohuan Zhu et al.

Accretion governs the growth of young stars and the early evolution of their circumstellar disks, yet population-level measurements of accretion are often hampered by heterogeneous diagnostics and by samples preferentially selected toward disk-bearing or accreting objects. This can impact the mass accretion rate-stellar mass ($\dot{M}$-$M_\star$) relation, particularly at substellar masses. We present a uniform analysis of accretion in the $\sim$2 Myr-old star-forming cluster IC 348 based on dee…

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astro-ph.EPastro-ph.IM2026年9月5日

Rotational broadening of exoplanet spectra in arbitrarily oriented systems: Application to reflected light

Sophia R. Vaughan, Laura Kreidberg

Exoplanet reflection spectra contain a wealth of information, which we are now beginning to access. At a high spectral resolution, the rotation of both the star and the planet affects the shape of the reflected spectral lines. This effect must be accounted for in high-resolution analyses and could be used to measure the orbital alignment of systems. In this work, we derive the rotational broadening kernels for arbitrarily aligned systems, both for the stellar spectrum viewed by the planet and fo…

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