研究動向

astro-ph.GA2026年8月12日

Search for a Globular Cluster whose Passage through the Galactic Disk could Trigger the Radcliffe Wave

V. V. Bobylev, A. T. Bajkova

Using a catalog of 152 globular clusters (GCs), their orbits were constructed to determine their intersections with the Galaxy's plane of symmetry. Young open star clusters (OSCs) were selected from the selection zone characteristic of the Radcliffe wave. The Hunt and Reffert catalog served as the source of data on these OSCs. A grouping of 17 OSCs with an average age of 32.7 million years was found. It is compact in coordinate, velocity, and age space. This grouping is shown to be a good candid…

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astro-ph.HEastro-ph.GA2026年8月12日

Constraining the gamma-ray efficiency of LINER outflows with Fermi-LAT and MEGARA

Alberto Domínguez, Alejandra León, Adithiya Dinesh, Armando Gil de Paz

Low-Ionization Nuclear Emission-line Regions (LINERs) commonly host ionized gas outflows, but their role as high-energy particle accelerators remains debated, particularly following the very-high-energy $γ$-ray detection of NGC 4278, which implied extreme radiative efficiencies. We empirically determine the $γ$-ray radiative efficiency of a local sample of LINERs to test whether their high-energy emission can be powered by extended ionized outflows or requires compact nuclear jets. We combine sp…

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physics.plasm-phastro-ph.SRcond-mat.stat-mech2026年8月12日

The Ambipolar electric field in multispecies plasma atmospheres: effects of alpha particles and stochastic heating

Luca Barbieri, Pascal Démoulin, Daniel Verscharen

We investigate stationary states of a collisionless, gravitationally stratified plasma atmosphere composed of electrons, protons, and alpha particles by extending Pannekoek--Rosseland theory to multispecies and multi-temperature plasmas. Starting from Liouville's theorem, we derive the self-consistent ambipolar electric field from kinetic equilibrium and charge neutrality. For a single-temperature atmosphere, we obtain analytical expressions for the ambipolar field, show its dependence on alpha-…

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astro-ph.HE2026年8月12日

Identification of a Large-Scale Diffuse Gamma-Ray Structure in the Southern Galactic Hemisphere

Zhen Xie, Xiaoyuan Huang, Bing Liu, Ruizhi Yang

We identify and characterize a large-scale diffuse gamma-ray structure in the Southern Galactic Hemisphere using 17 yr of Fermi-LAT data. An energy-dependent likelihood analysis, including alternative Galactic diffuse-emission models, isotropic emission, the Fermi bubbles, and resolved 4FGL sources, reveals an extended excess that persists across the tested background models and spans tens of degrees. The excess broadly follows the X-ray-defined southern eROSITA Bubble (eB) region, while also ov…

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astro-ph.EP2026年8月12日

Evolutionary tracks of giant planets formed by disk instability

Mirco Bussmann, Ravit Helled

The evolution of giant planets depends on their formation history. While several evolutionary models self-consistently link planet formation by core accretion to long-term evolution, such models for planets formed by disk instability are lacking. We simulate the evolution of giant planets formed by disk instability and follow their evolution including the pre-collapse phase, dynamical collapse, and long-term contraction in a unified numerical framework. The evolution is simulated using the MESPA…

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astro-ph.SR2026年8月12日

Deep MUSE observations of SNR 0509-67.5 reveal a double degenerate merger progenitor

Priyam Das, Ivo R. Seitenzahl, Gilles Ferrand, Rudiger Pakmor, Simon J. Murphy, Ashley Ruiter, Brian P. Schmidt, Friedrich K. Roepke et al.

Deep MUSE observations of SNR 0509-67.5 reveal that the coronal [Fe\,\textsc{xiv}] $\mathrmλ$5303 emission line appears with either one or two velocity components across the entire remnant, arising from reverse-shocked ejecta moving toward and away from the observer. A supervised dense neural network classifies each spaxel and fits Gaussian profiles plus a linear function to the observed line emission. We measure a bulk Doppler velocity of $-1000\pm60~~\mathrm{km~s^{-1}}$, interpreted as the lin…

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astro-ph.HEastro-ph.GAmath-phphysics.comp-ph2026年8月12日

Spiral structure from the interference of gravitational eigenmodes in ultralight dark matter halos

Jacob Reinach, Hubert Bray

We use a variety of analytic and numerical techniques to approximate the geometry of individual dark matter halos when modeled as collections of ultralight scalar bosons (ULDM), followed by an analysis on the future directions and implications of this work. Ultimately, we aim to understand the morphology and creation of complex structures (like spirals) in galaxies from a geometric standpoint and to investigate the connection between dark matter and baryonic matter in galaxies. We find that supe…

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astro-ph.HE2026年8月12日

Discovery of 27 new Rotating Radio Transients by MeerTRAP

S. Singh, J. Tian, B. W. Stappers, K. Shaji, K. M. Rajwade, L. Levin, J. D. Turner, M. C. Bezuidenhout et al.

We present the discovery of 27 new Galactic transients made by the commensal MeerTRAP single pulse search programme at the MeerKAT telescope. We determine the location of 14 of these discoveries with arcsecond accuracy by imaging the data captured in the dedicated transient buffer. A preliminary estimate of the period was made for 8 sources using the arrival times of several pulses detected by MeerTRAP. The periods of these transients range between 0.78 s and 4 s. For the previously published Me…

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astro-ph.SR2026年8月12日

New constraints on the binary system HD 327083 and its gaseous and dusty environments

L. Cidale, P. Marchiano, M. Kraus, I. Andruchow, M. L. Arias, M. Cure, M. Borges Fernandes, Y. Aidelman et al.

Binary systems with circumbinary molecular and dust rings are of great interest because they provide insights into the dynamics and evolution of stellar systems and the chemistry of the surrounding material. We aim to elucidate the nature of the B[e] binary system HD 327083 and the physical properties of its circumstellar and circumbinary envelopes. We combined multi-epoch high-spectral resolution optical and near-IR observations with VLTI/MIDI observations and ASAS-3 photometry. The data were a…

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astro-ph.SRastro-ph.HE2026年8月12日

Chemical fingerprints of binary mass transfer in massive stars

Harim Jin, Norbert Langer

The majority of massive stars are born in close binary systems. As stars expand when they age, mass transfer or even a merger with their companion is inevitable. However, most binary interaction products appear as single stars, such that the main evidence of their exciting past is lost. In a comprehensive grid of detailed massive binary evolution models we find systematic trends in chemical surface abundances that allow identifying the past mass gainers. We develop an analytic framework which is…

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astro-ph.GA2026年8月12日

Classifying Quasar Types Without a Spectrum

Adrien Hélias, Pauline Barmby, Sarah C. Gallagher, Shahram Abbassi, Matthew J. Graham

Distinguishing between Type 1 and Type 2 quasars is important because it helps us understand accretion regimes, black hole mass scaling, disk instabilities and feedback processes in active galaxies. Although spectroscopy provides robust classification, it does not scale well with the millions of quasars observed in modern surveys, as it requires substantial time and resources to acquire a good spectrum. On the photometry side, quasar light curves are always irregularly sampled and affected by th…

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astro-ph.SR2026年8月12日

1.5D investigation of the Hanle effect in the Ca I 4227 line using partial frequency redistribution. Comparison of synthetic Stokes profiles in Bifrost and MURaM-ChE rMHD models

Devang Agnihotri, L. S. Anusha, D. Przybylski, R. H. Cameron, S. K. Solanki

Modeling scattering polarization in the Ca I 4227 Å line is important for diagnosing chromospheric magnetic fields. We investigate the relative influence of formation heights and magnetic fields, through the Hanle effect, on spatially averaged synthetic Stokes profiles using realistic solar atmospheres. We employ 1D vertical columns from 3D radiative magnetohydrodynamic simulations of the solar chromosphere performed with the Bifrost and MURaM-ChE codes, and solve the 1.5D non-local thermodynami…

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astro-ph.EPastro-ph.SR2026年8月12日

Three new exoplanet systems from the Dispersed Matter Planet Project

J. R. Barnes, C. A. Haswell, Z. O. B. Ross, E. Rutherford, M. R. Standing, A. T. Stevenson, D. Staab, L. Fossati et al.

We present a radial velocity analysis of three bright, low-activity stars identified by the Dispersed Matter Planet Project (DMPP). We use a Bayesian framework to compare purely Keplerian models with models incorporating stellar activity via a quasi-periodic Gaussian Process (GP). DMPP-7 (HD 118006) is a slightly evolved star that harbours a single 0.72 Saturn-mass giant ($m_\textrm{p}\sin i$ = 69 M$_\oplus$) with an orbital period of P = 4.93 d. A longer 21 d - 22 d period cannot be conclusivel…

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astro-ph.SR2026年8月12日

First and Comprehensive Study of V0757 Pup : $γ-$Doradus Pulsator in Detached Eclipsing Binary

Bakuh Danang Setyo Budi, Bryant Randolph, Rafa Nanda Akilah, Evan Irawan Akbar, Hakim Luthfi Malasan, Puji Irawati

Pulsating stars in detached eclipsing binary (EA) systems are known for providing many important physical informations which constrain both stellar structure and evolution theories. To date, fewer than 50 $γ$ Doradus (GDOR) stars have been found in eclipsing binary systems, making them important targets to study \textit{g}-mode pulsation inside the stars. We present a comprehensive physical and pulsational analysis of V0757 Pup (TIC 6939791), a detached eclipsing binary system observed by the TE…

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astro-ph.EP2026年8月12日

Chemical Tracers for 3D Atmospheric Asymmetries on WASP-69 b

Nidhi Bangera, Ludmila Carone, Vikas Soni, Kenneth Goodis Gordon, Luca Fossati, Helena Lecoq-Molinos, Paul B. Rimmer, Peter Woitke et al.

Warm giant exoplanets exhibit strong three-dimensional temperature contrasts that can significantly alter atmospheric chemistry through quenching and photochemistry, yet transmission spectra are commonly interpreted using one-dimensional, limb-averaged models. Such simplifications may bias inferred atmospheric properties, particularly metallicity and C/O ratio. In this work we investigate the relative influence of atmospheric composition and three-dimensional thermal structure on atmospheric che…

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astro-ph.IMastro-ph.HE2026年8月12日

SPORE: An Event-Level Sampling Pipeline for Multi-Telescope Neutrino Astronomy

Jeffrey Lazar, Perrine Wilmet, Gwenhaël de Wasseige

We present an open-source Python package for simulating neutrino events from astrophysical point and extended sources using tabulated instrument response functions (IRFs). The package encodes three detector response components - effective area, point spread function, and energy resolution - in a selection-agnostic HDF5 format, which can represent a neutrino telescope whose response is supplied in that form, whether from a public release or a private study. Sampling algorithms cover point sources…

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astro-ph.SR2026年8月12日

Results from the first spectropolarimetric survey of $γ$ Dor pulsators

J. Labadie-Bartz, R. Ouazzani, C. Neiner, V. Antoci, P. Stanley, T. Natan, K. Thomson-Paressant, S. D. Chojnowski et al.

Context. Magnetic fields can have an important influence on stellar structure and evolution. In intermediate-mass (A- and F-type) stars, there are many known stars with directly measured strong, globally organized magnetic fields, as well as indications of weak and/or small-scale variable fields. However, among the intermediate-mass $γ$ Dor pulsators, there are no known stars with strong surface magnetic fields. Aims. The broad goal of this work is to search for evidence of strong, globally orga…

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gr-qcastro-ph.IM2026年8月12日

Taiji Resolving Power for the Transverse Scalar Mode of Gravitational Waves

Bo-Xuan Ge, Zhoujian Cao

We investigate how small a co-propagating transverse-scalar component can be resolved by Taiji in an already identified bright tensor chirp. Using a source-tracked tensor-null response, we formulate the problem in terms of the minimum resolvable scalar strain fraction and evaluate it over the sky. For a one-year benchmark chirp with tensor signal-to-noise ratio $ρ_T=1000$, we find that Taiji can rule out transverse-scalar strain fractions $ε_b\gtrsim0.532\%$ at the all-sky median level. The thre…

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astro-ph.SR2026年8月12日

Statistics of Solar Filament Mass based on CHASE Sun-as-a-star Spectroscopic Observations

T. Y. Xie, Z. H. Zhao, X. Cheng, Y. H. Chen, Z. Zheng, Q. Hao, C. Li, M. D. Ding et al.

Filaments are cool and dense plasmas suspended in the hot corona of the Sun and other stars. Accurately estimating their masses is of great significance for understanding subsequent eruptions and induced space weather effects, but it remains hindered by their intrinsic geometric uncertainties, particularly in spatially unresolved stellar observations. To test and calibrate the methods for estimating the masses of stellar filaments, we conduct a statistical Sun-as-a-star analysis of solar filamen…

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astro-ph.EP2026年8月12日

Infrared-to-visible albedo ratio of Phobos: Comparison with primitive asteroids

T. J. Dyer, J. Beccarelli, M. Delbo, C. Avdellidou, M. Pajola, A. Milton, A. Lucchetti, G. Munaretto et al.

Aims. The ratio between infrared and visible albedo, pIR/pV, provides a simple proxy for the spectral slope of asteroid surfaces between the visible and near-infrared wavelength ranges. The aim of this work is to assess whether the different spectral units of Phobos occupy the same spectral parameter space as the primitive asteroid populations in order to confirm or not its possible asteroidal origin. Methods. For each of the three spectral units of Phobos (Red, Transitional and Blue), we extrac…

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astro-ph.HE2026年8月12日

Radio flares and X-ray hardening embedded in the long soft state of 4U 1543-475

Zuobin Zhang, Rob Fender, Jiachen Jiang, Payaswini Saikia, David M. Russell, Andrew Hughes, Honghui Liu, Francesco Carotenuto et al.

We present a comprehensive multi-wavelength study of the black hole X-ray binary 4U 1543-475 during its 2021 outburst, focusing on radio flaring episodes that are commonly interpreted as signatures of episodic jet production and are embedded within states when the X-ray emission was dominated by an accretion disk component. The radio monitoring reveals at least two discrete flares that coincide with periods of enhanced Comptonized X-ray emission. Broadband spectral modelling shows a significant…

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astro-ph.HE2026年8月12日

Cherenkov light as a mechanism for light flashes seen by astronauts in space

Dominika Švecová, Pavol Bobík, Blahoslav Pastirčák

Astronauts first reported light flashes during the Apollo 11 mission. These events have since been associated with cosmic rays, although their underlying mechanism remains uncertain. This study investigates possible formation processes using Geant4 simulations of cosmic ray interactions in a simplified model of the human eye. We apply published models of human visual perception to the simulated particle induced photons and compare the resulting light flash rates with experimental observations. O…

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astro-ph.GA2026年8月12日

Molecule-specific diffusion and desorption of interstellar ices on carbonaceous dust

Yi-Hsuan Chiu, Tushar Suhasaria, Cornelia Jäger, Chun-Yi Lee, Ko-Ju Chuang, Thomas Henning, Yu-Jung Chen

Interstellar ices form on dust grains in the coldest regions of molecular clouds and preserve key volatile reservoirs that could be incorporated into protoplanetary disks during star and planet formation. However, the effect of the dust surface composition on the ice structure and spectroscopic behavior remains poorly constrained. We present a comparative laboratory study of astrophysically relevant ices (CO, CO2, and H2O) deposited on inert calcium fluoride (CaF2) substrate and carbonaceous dus…

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astro-ph.EP2026年8月12日

Altered Cosmic Organics as Venus' Ultraviolet Absorbers

Rakesh Mogul, Mikhail Yu. Zolotov, Michael J. Way, Sanjay S. Limaye

Venus' ultraviolet (UV) absorbers significantly contribute to the atmosphere's energy budget. However, the composition of these absorbers remains a mystery. Here, we show that mixtures of polycyclic aromatic hydrocarbons (PAHs) and iron-bearing compounds, analogs of altered cometary dust, excellently match Venus' spectra from the cloud tops to the sub-cloud atmosphere across the UV and visible wavelengths. The molecular compositions for the cloud tops (5-10 ring PAHs and ferric chloride), decomp…

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astro-ph.IMastro-ph.HEgr-qc2026年8月12日

LIGO A$^\sharp$: Detector Design and Science Prospects Beyond A+

L. Sun, K. Kuns, B. J. J. Slagmolen, P. Fritschel, P. Schmidt, B. T. Lantz, S. S. Y. Chua, Divyajyoti et al.

We present the LIGO A$^\sharp$ detector concept, an upgrade for the LIGO observatories based on room-temperature interferometers beyond the fifth observing run (O5). Building on the A+ sensitivity, A$^\sharp$ targets broadband sensitivity improvements through heavier test masses, improved suspensions and seismic isolation, increased arm-cavity power, enhanced frequency-dependent squeezing, reduced coating thermal noise considering two scenarios, and improved control of mechanical motion and opti…

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astro-ph.SR2026年8月12日

Disco in the Dust: Reflected light at the bow shock around Betelgeuse's companion explains its observed luminosity

Jared A. Goldberg, Meridith Joyce, Anna J. G. O'Grady, Sam D. Barber, Logan J. Prust, Mitchell Dennis, László Molnár, Christian I. Johnson et al.

Recent detections of $α$ Orionis B, the putative companion to Betelgeuse, have been reported using multiple instruments and techniques. These include, most recently, a $>6σ$ detection using VLT/SPHERE reported by Montarges+2026. The authors infer a bright companion ($\sim10^{-3}\times$ Betelgeuse's luminosity) with a mass of $2-3\,M_\odot$ and $T_\text{eff}\approx10-12{,}000$\,K, loosely consistent with the uppermost bounds of Howell+2025's recent mass estimate from speckle-imaging. However, it…

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astro-ph.IM2026年8月12日

Towards Genuine Coexistence: Per-Satellite Emission and Radiation Limits to Protect Radio Astronomy and Geodetic VLBI at 1-14 GHz from Satellite Constellations

Balthasar Indermuehle, Lucia McCallum, Emma van der Wateren, Hayo Hase, Benjamin Winkel, Liroy Lourenco, Federico Di Vruno, Michael Lindqvist et al.

Geodetic very long baseline interferometry (VLBI) is a vulnerable application of the radio astronomy service (RAS): it provides the fundamental link between the celestial and terrestrial reference frames, and is the only technique that uniquely determines UT1-UTC. The next-generation geodetic VLBI Global Observing System (VGOS) achieves millimetre accuracy by synthesising group delay across 3-14 GHz using 32x32 MHz channels, most of which lie outside RAS primary allocations. The SNIFFLES-I surve…

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astro-ph.HE2026年8月12日

A Radiation-Hydrodynamic Light Curve Grid and Interpolation Framework for Stripped-Envelope Supernovae

Qiliang Fang, Takashi J. Moriya

We present a grid of 8,148 stripped-envelope supernovae (SESNe) light curves based on radiation hydrodynamic simulations of exploding helium-star progenitors. The grid spans an ejecta-mass range representative of typical SESNe, together with broad ranges of explosion energies, radioactive nickel masses, and degrees of material mixing. We systematically investigate how these physical parameters shape the light curves and develop an interpolation-based parameter inference framework that enables th…

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astro-ph.EPastro-ph.IM2026年8月12日

Dynamic Trajectory Analysis of Meteoroids Showing Minimal Deceleration

Thomas Stevenson, Ellie Sansom, Hadrien Devillepoix, Maria Gritsevich, Anna Zappatini, Peter Jenniskens, Christopher Herd, Jonti Horner et al.

Meteoroids decelerate and ablate as they descend through the atmosphere, however a portion of instrumentally observed meteors show little measurable deceleration and remain poorly characterised. These are referred to as minimally decelerating objects (MDOs). The traditional alpha-beta method of dynamic trajectory analysis cannot reliably determine their preatmospheric masses or rates of ablation. We present a new approach for estimating the ballistic coefficients (alpha) and mass loss parameters…

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gr-qcastro-ph.HEhep-ph2026年8月12日

Constraints on ultralight bosons from merging binary and remnant black holes observed during the second and third parts of the fourth LIGO-Virgo-KAGRA observing run

The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, A. G. Abac, A. Abe, I. Abouelfettouh, F. Acernese, K. Ackley et al.

We present constraints on ultralight bosons using binary black hole mergers observed in the second and third parts of the fourth LIGO-Virgo-KAGRA observing run. Directed searches are conducted for long-transient gravitational waves from ultralight vector boson clouds around merger remnants, using a hidden-Markov-model (HMM) tracking scheme. We target the remnant black holes formed in the binary coalescences that produced GW250114 and GW250207. We find no evidence for such signals from either tar…

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