研究動向

astro-ph.HE2026年9月8日

Constraints on the Low-frequency Radio Emission of the Galactic FRB Source SGR 1935+2154

Chen-Ran Hu, Jinhuang Cao, S. A. Tyul'bashev, Pei Wang, Yong-Feng Huang, E. A. Brylyakova, G. E. Tyul'basheva, Jin-Jun Geng et al.

We present a search for radio pulses from the Galactic magnetar SGR 1935+2154, a well-known source of fast radio bursts (FRBs), at $\sim$110 MHz using the Large Phased Array (LPA) of the Pushchino Radio Astronomy Observatory. Data from two active periods in 2020 (March -- May and September -- November, with $\sim 3.5$ minutes of daily coverage) were analyzed with new methods tailored to both FRB-like single pulses and pulsar-like periodic signals. No significant FRB-like pulses were found. Using…

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astro-ph.GA2026年9月8日

The environmental dependence of the circumgalactic medium in a high-resolution cosmological simulation

Georg Herzog, Rajeshwari Dutta, Michele Fumagalli

There is increasing evidence from observations that the circumgalactic medium (CGM) of galaxies depends on the large-scale structure in which they are embedded. When probing the CGM in absorption using quasar sightlines, studies find an enhanced sky coverage in the CGM of galaxies in overdensities compared to galaxies in isolation. However, the exact reason for this environmental dependence is still unclear. In this work we aim to model for the first time the influence of the large-scale structu…

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astro-ph.EPastro-ph.SR2026年9月8日

XUE. ProDiMo models of internally and externally irradiated planet-forming disks around 0.3-4.0 solar mass stars (The IRIS project I)

Jenny Frediani, Konstantin V. Getman, Peter Woitke, Bayron Portilla-Revelo, Eric D. Feigelson, Christian Rab, Arjan Bik, María Claudia Ramírez-Tannus et al.

Most stars and planets form in massive star-forming regions, where disks are exposed to external far-ultraviolet (FUV) radiation from nearby O- and B-type stars. The combined effects of stellar irradiation and external FUV fields on terrestrial planet-forming regions (< 10 au) across stellar masses remain unclear. We investigate how internal UV and X-ray irradiation and external FUV fields affect mid-infrared (mid-IR) gas emission and the atmospheric carbon-to-oxygen (C/O) ratios inferred in T T…

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astro-ph.HEgr-qchep-phnucl-th2026年9月8日

Decoding the Imprints of Energy-Momentum Squared Gravity in Neutron Stars with Machine Learning Analysis

Sayantan Ghosh, Premachand Mahapatra, Dipti Deb

Neutron stars (NSs) provide a unique laboratory for testing gravity in the strong-field regime and for searching for deviations from General Relativity (GR). In this work, we investigate the effects of Energy-Momentum Squared Gravity (EMSG) on NS structure and examine whether its signatures can be identified from observable stellar properties using supervised machine learning (ML). We solve the modified Tolman-Oppenheimer-Volkoff equations for approximately $10^{4}$ nuclear equations of state (E…

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astro-ph.IMastro-ph.COastro-ph.HEastro-ph.SR2026年9月8日

A Missing Tool for Calculating Auto/Cross-correlation Function under Nonuniform Sampling Observations

Chen-Ran Hu, Yong-Feng Huang, Jin-Jun Geng, Orkash Amat, Ze-Cheng Zou, Chen Deng, Fan Xu, Xiao-Fei Dong et al.

Nonuniform sampling presents a long-standing challenge in astrophysical time-domain analysis, invalidating the standard autocorrelation and cross-correlation functions and forcing researchers to adopt ad-hoc methods like interpolation or binning, which introduce unquantified biases and lack rigorous error estimation. Here we introduce a new method for calculating the nonuniform autocorrelation function (NUACF) and nonuniform cross-correlation function (NUCCF) for irregularly sampled time series.…

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

Radial velocity follow-up of \textit{Gaia} astrometric substellar companions: six confirmed brown dwarfs and 13 impostor binaries

Marcus L. Marcussen, Simon H. Albrecht, Kamil K. Kalinowski, Joshua N. Winn, Guðmundur Stefánsson, Jens Reersted Larsen, Julie Gadeberg, Evan Fitzmaurice et al.

With microarcsecond precision, \textit{Gaia} has made the astrometric discovery of substellar companions feasible. However, follow-up observations are needed to check on orbital solutions and rule out astrophysical false positives. We validate and characterise a sample of 20 \textit{Gaia} Data Release 3 (DR3) astrometric candidates for substellar companions, with the dual goal of identifying false positives and deriving robust physical parameters for genuine companions. We performed high-resolut…

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astro-ph.EPastro-ph.IMcs.DB2026年9月8日

MAD-LEO: A Maneuver-Annotated Orbital Dataset for LEO Satellites with Tiered Multi-Source Evidence

Zhixin Guo, Qi Shi, Xiaofan Xu, Linqiang Ge, Hua Zhu, Liyan Ben, Bendian Nie, Yuanrui Zhao et al.

With the rapid development of aerospace technology and the large-scale deployment of low Earth orbit (LEO) constellations, the risk of orbital collisions has increased, creating a growing demand for reliable observations of satellite maneuvers. However, public datasets containing real maneuver records remain scarce. We present MAD-LEO, a Maneuver-Annotated orbital Dataset for LEO satellites. The mission-reported subset contains 1,134 maneuver events from eleven geodetic and altimetry satellites…

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cs.SCastro-ph.GAphysics.comp-ph2026年9月8日

Physical Law Ecology: mapping multi-mechanism ecologies as the zeroth step of data-driven scientific discovery

Xiongheng Bian, Xiangyu Cui, Ma Feng, Xiaoyan Shen

Every data-driven equation discovery method assumes (implicitly and without verification) that the target system obeys a single governing law ($K{=}1$). Here we show that this assumption is the primary bottleneck limiting scientific discovery in multi-mechanism systems, and introduce Physical Law Ecology, a framework that makes $K^*$ (the number of coexisting independent mechanisms) itself the first quantity to be determined from data. The framework automatically mines a pool of topologically di…

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astro-ph.HE2026年9月8日

Nuclear equation-of-state effects on the two-dimensional post-outburst thermal evolution of magnetized neutron-star crusts

Wei-Feng Zhang, Zhi-Fu Gao, Wen-Qi Ma, Na Wang, Yan-ling Liu

We present a controlled two-dimensional study of nuclear-equation-of-state (EOS) effects on the post-outburst thermal relaxation of magnetized neutron-star crusts. Six EOS models are evolved at a fixed gravitational mass of $1.4 M_{\odot}$ with EOS-specific TOV backgrounds, crust compositions, and transport inputs under identical magnetic-field and heating prescriptions. Our analysis combines self-consistent multi-EOS evolution with a BSk-family factorization that separates structural, microphys…

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astro-ph.GA2026年9月8日

J023721.13$-$010528.5: A Giant $S$-shaped Radio Galaxy Showing Four Episodes of Jet Activity

Pavan Vijay Khadekar, Dharam Vir Lal, Ramana Athreya

We present high-sensitivity, high-resolution radio observations of J023721.13$-$010528.5 using the upgraded Giant Metrewave Radio Telescope in band-3 (250--500\,MHz) and band-4 (550--950\,MHz), along with MeerKAT (1280\,MHz) and VLA (3\,GHz) survey images. The radio source, hosted by a bright cluster galaxy at redshift $z=0.372$, is a giant radio galaxy with a projected linear size between the outermost hotspots of 1.2~Mpc and is one of the largest $S$-shaped radio sources known. Its radio morph…

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hep-phastro-ph.SR2026年9月8日

A distance-independent constraint on the axion-electron coupling from RGB stars

Thomas Levasseur, Oscar Straniero, Andrea Caputo

Interest in axions and axion-like particles has resurged, driven by their role in solving the strong CP problem and their appeal as dark matter candidates. The luminosity of the tip of the red giant branch (TRGB) offers a key observable for probing these particle properties. This work aims to improve existing bounds on the axion-electron coupling by adopting a differential observable that is less sensitive to distance, interstellar extinction, the zero-point of bolometric corrections (BCs), and…

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astro-ph.SR2026年9月8日

Magnetic Signatures in Merger Products

Nicolas Muntean, Lisa Bugnet, Lynn Buchele, Debasish Dutta, Lukas Einramhof, Paul G. Beck, Lucas Barrault, Bastien Liagre et al.

Asteroseismic estimates of the magnetic field strength in the radiative interior of red giant stars depend strongly on the internal stellar structure derived from models. Since red giant branch merger products have been shown to be able to possess a different core structure than single stars of the same mass, we investigate how a mass-gain history influences our estimates of an internal magnetic field strength. We construct stellar models with and without a mass-gain event after the onset of the…

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astro-ph.HE2026年9月8日

Sharpening the Mass Measurement of PSR J1048+2339 via High-Cadence Photometry

Kwan-Lok Li, Ka-Yui Au, Lupin C. C. Lin, C. Y. Hui, Albert K. H. Kong, Jumpei Takata

Neutron stars are among the densest objects in the universe, and the mass measurements are crucial to the understanding of their equation of state. Pulsars in tight binaries can be weighed dynamically, but accurate mass estimates are often hampered by uncertainties in orbital inclinations. In this paper, we report on multi-epoch optical monitoring of the pulsar binary, PSR J1048+2339, using the 0.5-m RIFT telescope at Lulin Observatory. Our observations reveal frequent optical flares with eclips…

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astro-ph.HEgr-qc2026年9月8日

Near-Horizon Tidal Disruption Events

Yang Yang, Xian Chen

Tidal disruption events (TDEs) offer a unique dynamical probe of the spacetime geometry around supermassive black holes (SMBHs). While conventional TDEs occur around SMBHs of $M_\bullet \sim 10^6 - 10^7 M_\odot$, where stars are disrupted far from the event horizon, here we identify a special class of TDEs around rapidly spinning SMBHs with masses $M_\bullet \gtrsim 10^8 M_\odot$, where the tidal-disruption radius approaches the gravitational radius. We term these events "near-horizon TDEs" and,…

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astro-ph.GA2026年9月8日

The Impact of Circumgalactic Rotation on Ly$α$ Radiative Transfer

Hee-Gyeong Kym, Seok-Jun Chang, Max Gronke, Kwang-Il Seon

Hydrogen Lyman-alpha (Ly$α$) is a prominent emission line from the circumgalactic medium (CGM). Due to its resonant nature, Ly$α$ carries imprints of the physical properties and kinematics of the cold CGM. In particular, CGM rotation can modify the Ly$α$ peak separation, which is often interpreted as a tracer of H I column density. We present 3D Monte Carlo Ly$α$ radiative-transfer simulations in a CGM-like rotating medium and examine how the emergent spectra depend on rotational velocity ($V_{\…

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astro-ph.GAastro-ph.SR2026年9月8日

Series of core collapse numerical simulations (SOLANUM) I: Modelling the early and late infall in a sun-like protostar

D. Navarro-Almaida, B. Commerçon, U. Lebreuilly, P. Hennebelle, A. Ahmad, A. Fuente, P. Rivière-Marichalar, J. E. Pineda et al.

Magnetohydrodynamical simulations and interferometric observations toward young stellar objects reveal the accretion of gas that may alter the physical properties and chemical composition of protostellar disks. Our goal is to constrain the physical history and properties of late infalling gas, and assess its potential to change the physical and chemical properties of the disk. We carried out a core collapse simulation of 5 M$_{\odot}$ of gas endowed with tracer and sink particles during $\sim 3.…

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astro-ph.HEastro-ph.SR2026年9月8日

SN 2025fhm: A central-engine powered Ic-BL supernova associated with X-ray transient EP250304a

Cui-Ying Song, Nan Jiang, Xiaofeng Wang, Yi-Han Iris Yin, Lingzhi Wang, Wenxiong Li, Shengyu Yan, Dae-Sik Moon et al.

We present X-ray, optical, and radio follow-up observations of EP250304a, an extragalactic fast X-ray transient (EFXT) discovered by the Einstein Probe. Its X-ray light curve exhibits two broad pulses with comparable peak fluxes within the first $\sim$1~ks, a feature rarely seen among low-luminosity gamma-ray bursts or EFXTs. Optical follow-up observations were carried out using the Korea Microlensing Telescope Network, the Thai Robotic Telescope, the Las Cumbres Observatory 1~m global network,…

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astro-ph.HE2026年9月8日

Radio Emission with Dust: A Bow-Shock Interpretation for the TDE Candidate AT 2019avd

Shuyuan Wei, Yanan Wang, Guobin Mou, Linhui Wu, Santiago del Palacio, Ranieri D. Baldi, Xiaolong Yang, Yang Huang et al.

Forward shocks produced by interactions between a single ejected blob and the circumnuclear medium (CNM) around a supermassive black hole are widely invoked to explain radio emission from tidal disruption events (TDEs). However, recent observational evidence such as rapidly rising radio emission, double-peaked broadband spectral energy distributions, and declining shock energies at late times poses challenges to this picture. Alternative scenarios have therefore been proposed, including bow shoc…

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astro-ph.SR2026年9月8日

Detection of resonant nodes in a pore chromosphere

T. Felipe, H. Kumar, E. G. Broock

Active region atmospheres host many oscillatory phenomena. The chromosphere is delimited by steep temperature gradients at the photosphere and transition region, where magnetoacoustic waves are trapped and can form standing oscillations within this resonant cavity. We aim to detect the signature of the resonant nodes of standing waves, which are expected to produce sudden jumps in the oscillatory phase and power dips. Spectroscopic temporal series of H$α$ in a pore were acquired with the Swedish…

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astro-ph.GAastro-ph.HE2026年9月8日

Low-Redshift Interlopers in the SDSS DR16 $z > 5$ Quasar Catalogue

Vivek Kumar Jha, Harikumar N, Yogesh Wadadekar

High-redshift quasars ($z>5$) are crucial for studying early black hole growth and reionisation. SDSS Data Release 16 catalogues 655 such sources with multiple redshift estimators. We systematically examined this subsample and found 480 sources (73.2\%) where pipeline redshift (Z\_DR16Q) disagrees with the derived estimate (Z\_FIT) significantly. Visual inspection confirms that 125 of these (19.1\% of the total) are actually low-redshift active galactic nuclei. In 114 cases, broad Mg\,{\sc ii} w…

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astro-ph.GA2026年9月8日

AEON-z5: A Candidate AGN-driven Outflow Enriching the Circumgalactic Medium at $z\simeq5.23$

Xiaoyang Wei, Zheng Cai, Shiwu Zhang, Fujiang Yu, Yunjing Wu, Shuaiyi Li, Xiaojing Lin, Mingyu Li et al.

The dispersal of chemically enriched gas from galaxies into their surroundings is a key process in galaxy evolution, yet direct observational evidence at z>5 remains scarce. We present AEON-z5, a galaxy at z~5.23 in the COSMOS field comprising a compact continuum-emitting core surrounded by an extended, line-dominated ionized nebula. JWST/NIRCam imaging shows that H$α$+[N II] and H$β$+[O III] emission extends to projected radii of >4 kpc - 2-2.5 times the typical effective radius at the host ste…

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astro-ph.HEastro-ph.CO2026年9月8日

Revisiting EBL Constraints from Gamma-Ray Observations: A Critical Assessment and Methodological Improvements

K. Abe, S. Abe, J. Abhir, A. Abhishek, V. A. Acciari, A. Aguasca-Cabot, I. Agudo, I. Albanese et al.

The extragalactic background light (EBL), ranging from the infrared to the ultraviolet bands, is the second most intense photon field in the universe, surpassed only by the cosmic microwave background (CMB). It is primarily generated by starlight in galaxies, either directly or through absorption by dust and re-emission at longer wavelengths. Very high energy (VHE, $E$ > $100\,$GeV) photons can be absorbed via $γγ$ interactions with the EBL during their propagation across cosmological distances,…

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astro-ph.GA2026年9月8日

The Roman eXtreme Deep Field (RXDF)

Haojing Yan, Anton M. Koekemoer, Yue Shen, Bangzheng Sun, Norman A. Grogin, Zihao Wu, Christian Kragh Jespersen, Rachel Somerville et al.

The Roman eXtreme Deep Field (RXDF) program is one of the five General Astrophysics Survey (GAS) programs approved for observing time with the Nancy Grace Roman Space Telescope in Cycles 1 and 2. It has been allocated 386.41 hours to carry out an imaging survey to AB = 30 mag (5-sigma) over ~140x larger area than the Hubble eXtreme Deep Field (HXDF) full-depth area (ACS+WFC3/IR). The RXDF will cover the full Roman wavelength range with 7 bands, reaching AB = 30 mag in RZYJH, 29 mag in F, and 28…

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astro-ph.HE2026年9月8日

From DAMPE to LHAASO: Rigidity Scales and Composition Changes in Galactic Cosmic Rays

Ruo-Yu Liu, Zhen Cao

This commentary briefly reviews recent measurements from DAMPE and LHAASO on cosmic rays to explore why the spectra of different species change shape across the TeV-PeV energy range. DAMPE finds that several primary nuclei show spectral softening at a similar magnetic rigidity, while the combined proton and helium data from DAMPE and LHAASO reveal a more complex evolution at higher energies. By comparing these spectral features and composition changes, we discuss what they may tell us about the…

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astro-ph.SR2026年9月8日

Multi-Height Spectropolarimetric Signatures of Magnetoacoustic Waves in Solar Plage

Taylor Sitterson, João M. da Silva Santos, Joshua Bentley, Tom Schad, Momchil Molnar, Bart De Pontieu, Juan Martinez-Sykora, Alexander G. M. Pietrow et al.

We analyze high-cadence spectropolarimetric observations of solar plage obtained with the Visible Spectro-Polarimeter (ViSP) on the Daniel K. Inouye Solar Telescope (DKIST) to investigate low-chromospheric waves sampled by the Na I D1 5896 Angstrom and Ca II 8542 Angstrom lines. Observations were taken at an oblique viewing angle, providing sensitivity to transverse motions. Magnetic oscillations within plage elements exhibit significant line-of-sight (LOS) RMS amplitudes of approximately 9 G on…

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astro-ph.IMastro-ph.CO2026年9月8日

CTree: Branch-wise compatible merger tree builder

Jinsu Rhee, Christophe Pichon, Yohan Dubois

We introduce a merger tree builder, CTree. Its key feature is the identification of progenitors using the evolutionary information encoded in object branches, rather than relying solely on the instantaneous particle membership in a single snapshot. In this sense, CTree can be described as a branch-wise merger tree builder. Specifically, CTree extracts particles associated with objects over a defined timescale and uses this information to compute the merit functions employed in the progenitor sea…

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astro-ph.SR2026年9月8日

Investigating the Light Curves of 5 Long Period Variable Stars: A Study Cross-Harmonics using VStar, MESA, and GYRE

G. M. Sherren, A. Cross, N. Steenken, R. Ignace, H. R. Neilson

Long Period Variables (LPVs) are Asymptotic Giant Branch stars with periods >100 days. Around one third to half of LPVs display a Long Secondary Period (LSP) that is 5-10 times the length of the main periods. The exact cause of LSPs are unknown, with one potential explanation lying in cross-harmonics caused by the interaction of two simultaneously occurring periods. In this paper, we use the Fourier analysis software VStar to examine the visual range photometric light curves obtained through the…

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astro-ph.SR2026年9月8日

Tidally perturbed pulsations in OO Dra

Niveditha Parthasarathy, Mikhail Kovalev, Randa Asa'd

We perform a pulsation analysis of OO Dra using Light Curve data from TESS and present the first identification of six dipole modes as doublets from the primary star in OO Dra. The phases and amplitudes of these pulsation modes were analytically reconstructed. Among the six identified doublets, four are pulsating in $Y_{10x}$ mode with pulsation axis along the tidal axis, and two in $Y_{10y}$ with a pulsation axis orthogonal to tidal axis and the angular momentum axis. Our findings suggest that…

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astro-ph.SR2026年9月8日

Investigating Potential Relationships Between Mass Transfer Indicators and $δ$ Scuti Pulsations in oEA Systems

E. Çelik, F. Kahraman Aliçavuş

We explored potential associations between ongoing mass transfer and the pulsation properties of $δ$ Scuti primaries in a sample of 17 oscillating eclipsing Algol systems. For this purpose, we combined binary modelling, updated O-C analyses, and frequency characterization based on TESS photometry. To ensure homogeneity, the $T_{\rm eff}$ of the components were derived using a consistent SED fitting approach. From the binary solutions and O-C diagrams, we determined the mass transfer indicators (…

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astro-ph.SRastro-ph.HE2026年9月8日

The Association of Solar Radio Bursts with Eruptive and Confined Flares

Stephen M. White, Maria D. Kazachenko, Edward W. Cliver

We classify the metric radio emission associated with eruptive (CME-associated) and confined flares using the sample of events between 2010 and 2016 identified by Kazachenko (2023). We find striking differences in the occurrence of radio bursts between the two classes of flare: for soft X-ray flare sizes above M1.4, confined flares largely lack Type II (1\% association rate) and Type IV (6\%) emission. Approximately 15\% of the sample of $\geq$M1.4 confined flares are associated with impulsive-p…

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