研究動向

astro-ph.GAastro-ph.COastro-ph.SR2026年9月25日

Breaking the AGB Color Degeneracy with Variability and H$_2$O: A Consistent Picture of AGB Chemistry, Dust, and the J-Region Across Environments

Caroline D. Huang, Massimo Marengo, Antonio Capodagli, Adam G. Riess, Louise Breuval, Stefano Casertano, Patricia A. Whitelock, Gagandeep S. Anand et al.

Resolved asymptotic giant branch (AGB) populations present many observational puzzles. We consider three often treated separately: photometric C/O classification boundaries must be redrawn empirically in new environments; hydrostatic model grids are too blue in bands sampling H2O absorption; and J-region (JAGB) luminosities can differ between fields of a single galaxy. Pulsation connects them into a coherent picture. Using SPHEREx spectroscopy of AGB stars in the Large Magellanic Cloud (LMC) wit…

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gr-qcastro-ph.HEhep-th2026年9月25日

Rotating Weyssenhoff fluids in linearized Einstein-Cartan theory

Emmanuele Battista, Salvatore Capozziello, Francesco Giovinetti

The Weyssenhoff fluid expands the ordinary perfect-fluid description of general relativity by taking into account the intrinsic spin of its constituent particles. Within the linearized regime of Einstein-Cartan theory, we investigate the exterior geometry produced by isolated slowly rotating Weyssenhoff fluids, i.e., sources endowed with both macroscopic and microscopic angular momenta. Our work represents an extension of the foundational analysis of Arkuszewski, Kopczy{ń}ski and Ponomariev, whi…

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eess.SYcs.ARcs.ETphysics.acc-phphysics.space-ph2026年9月25日

From Routing Delay Shifts to Silent Data Corruption: Neutron-Induced SEU Effects in AXI-Based Zynq UltraScale+ MPSoCs

Mostafa Darvishi

SRAM-based FPGA system-on-chip devices are vulnerable to single-event upsets (SEUs) in configuration memory, which may perturb programmable routing resources and degrade communication fabrics. In modern Zynq UltraScale+ MPSoCs, such routing disturbances can introduce small propagation delay shifts that remain logically transparent yet compromise AXI-based data transfers and lead to silent data corruption. Although routing delay degradation and AXI interconnect failures have been studied independ…

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astro-ph.IM2026年9月25日

FOTO: Figure-Level Semantic Search for Astronomy

Hurum Maksora Tohfa, Francisco Villaescusa-Navarro

Astronomy papers carry much of their content in figures, but literature search indexes text, so there is no way to find a plot by describing what it shows. We present FOTO, a figure-level search tool over 482,750 captions from 53,839 peer-reviewed astro-ph papers. Each figure is indexed once by its title and caption, embedded with a 110M-parameter open model that runs locally, and a large language model is applied only to the retrieved shortlist, where it verifies real figures rather than genera…

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astro-ph.SR2026年9月25日

The 91T/99aa-like Type Ia Supernova 2019vrq, Part II: 3D, Non-LTE, Low-Amplitude, Pulsating Delayed-Detonation Models of a Promising Standard Candle

Peter Hoeflich, Yi Yang, J. Craig Wheeler, Dietrich Baade, Aleksandar Cikota, Elham Fereidouni, Divya Mishra, Sagiv Shiber et al.

We analyze the overluminous, 91T/99aa-like Type~Ia SN 2019vrq, based on light curves(LCs) and spectropolarimetric time-series. We employ 3D-radiation-hydrodynamical, full non-LTE simulations of low-amplitude, radially-pulsating-off-center-delayed-detonations(PDD) of a possibly rotating near-M(Ch) mass white dwarf (WD) to reproduce the LCs and spectra. The progenitor originates from a 7 Mo main-sequence star of solar metallicity. The explosion yields 0.86Mo of 56Ni and 0.023Mo of 58Ni. The latter…

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astro-ph.GAastro-ph.SR2026年9月25日

Collisional excitation of E- and Z-ethanimine to model cold molecular clouds

Francesca Tonolo, Vivek Vijay, Ernesto Quintas-Sánchez, Adrian Batista Planas, Carolin Joy, Richard Dawes, François Lique, Dmitri Babikov et al.

Context. Ethanimine is a prebiotically relevant complex organic molecule that has been proposed as a key precursor of amino acids in the interstellar medium. To date, both its E and Z isomers have only been detected toward the Sgr B2(N) molecular cloud. The pronounced non-local thermodynamic equilibrium (non-LTE) effects predicted for this molecule require accurate collisional rate coefficients for reliable astrophysical modeling and future astronomical searches. Aims. We aim to provide the firs…

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astro-ph.IM2026年9月25日

Wavefront-Conditioned Photon Measurements for Exoplanet Spectroscopy: Contrast Limits and Conditional Gains

Slava G. Turyshev

A wavefront-sensor (WFS) prediction can select the photon measurement before detection or condition its likelihood afterward. This matters for reflected-light spectra requiring hundreds of hours, because subtracting residual starlight cannot remove its photon noise. In a two-mode, low-occupation model, isotropically distributed leakage makes planet-mode projection---ideal single-mode injection matched to the planet---the optimal fixed single-photon measurement, including unequal aligned backgrou…

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astro-ph.HE2026年9月25日

Spectral and Polarization Properties of Coherent Radio Emission from Relativistic Magnetized Pair Plasma Shocks

Yuanhong Qu, Joonas Nättilä, Lorenzo Sironi

Fast radio bursts (FRBs) are millisecond-duration radio transients whose emission mechanism remains an open question. The so-called synchrotron maser instability in relativistic magnetized shocks is a leading candidate for FRBs produced outside the compact object magnetosphere, yet its spectral and polarization predictions have not been systematically explored. We present three-dimensional particle-in-cell simulations of relativistic magnetized pair plasma shocks with upstream magnetization $σ>…

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astro-ph.HE2026年9月25日

Infrared Cavity Surrounding T Pyxidis: Evidence of a Nova Super-remnant?

Michael W. Healy-Kalesh, Matthew J. Darnley

Nova super-remnants (NSR) are shell-like structures spanning tens of parsecs that are predicted to grow around all recurrent novae as a result of repeated ejecta sweeping up the surrounding material. After the first NSR was discovered in the Andromeda Galaxy around M31N 2008-12a, a number of Galactic NSRs have been uncovered, as has the first NSR in the Large Magellanic Cloud. Here we report an apparent infrared cavity surrounding the Galactic recurrent nova, T Pyxidis, which we suggest may be a…

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astro-ph.GAastro-ph.HE2026年9月25日

A tidal disruption event in a quasar at redshift 7.19

S. Fujimoto, Q. Fei, G. B. Brammer, K. Inayoshi, V. Kokorev, L. C. Ho, R. Li, F. Walter et al.

We report a long-lived nuclear transient in GNz7q, a red quasar at $z=7.19$ powered by a $\sim3\times10^{7}\,M_\odot$ black hole and hosted by a compact, dusty starburst galaxy. The transient was identified in more than two decades of imaging with HST, Spitzer, and JWST. After a rapid rise, the source faded smoothly by $Δm\simeq1.1$ mag in the rest-frame ultraviolet over $\sim2$ rest-frame yr, with coherent, wavelength-dependent evolution across 1--5 $μ$m that places GNz7q above the 99.9th perce…

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astro-ph.GAastro-ph.COastro-ph.HE2026年9月25日

SN Helios: A Multiply Imaged Type II Supernova Opening Time-Delay Cosmography beyond redshift of 3

Seiji Fujimoto, Conor Larison, Justin D. R. Pierel, Lukas J. Furtak, Masamune Oguri, Adi Zitrin, Jose M. Diego, Keren Sharon et al.

We report the discovery and spectroscopic confirmation of SN Helios, a strongly lensed, multiply imaged Type II supernova (SN) at $z=3.34$ behind the galaxy cluster RXC J0018.5+1626. The transient was identified as a red F150W-dropout source (F277W = 26.1 mag) in JWST/NIRCam imaging taken on 2026 July 3 for the VENUS survey, with no counterpart in 2024 December imaging. Director's Discretionary Time observations on 2026 August 17 added second-epoch NIRCam imaging and a deep NIRSpec prism spectru…

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astro-ph.HEnucl-th2026年9月25日

Machine Learning $β$-decay Half-lives and Their Application to $r$-Process Observables

Mengke Li, Flora Wang, Jonathan Engel, Matthew Mumpowe, Rebecca Surman, Nicole Vassh

Accurately modeling $β$-decay half-lives of highly neutron-rich nuclei is a critical challenge for understanding $r$-process nucleosynthesis and the resulting kilonova light curves. We introduce a data-driven approach to model $β$ decay that uses Mixture Density Networks (MDNs) trained on the latest experimental measurements to extrapolate the half-lives of neutron rich nuclei. Unlike standard deterministic regression, the MDN directly parameterizes the probability distribution of the half-lives…

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astro-ph.HE2026年9月25日

Interaction of stellar dipole and disk magnetic fields in accretion-ejection systems

Somayeh Sheikhnezami, Sarah Aslani

We study jet formation from a magnetically diffusive, sub-Keplerian accretion disk threaded by different magnetic field configurations. We present two dimensional, axisymmetric MHD simulations in spherical coordinates employing the PLUTO code. Our results show that the reference simulation, in which the disk is threaded by an initial large scale poloidal magnetic field, reaches a quasi steady state and produces a well collimated jet.Both kinetic and magnetic torques are significant and evolve sm…

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astro-ph.SR2026年9月25日

Revealing Optically Hidden Companions to Intermediate-Mass Stripped Stars with Radial Velocities

Alexander Laroche, Maria R. Drout, Ylva Götberg, Bethany Ludwig, Dandan Wei, Peter Senchyna, Mathieu Renzo, Debasish Dutta et al.

The recent discovery of a population of intermediate-mass helium stars ($\sim$2-8 $M_\odot$) in the Magellanic Clouds has opened a new observational window into massive binary evolution. These hot, helium-rich stars are thought to be products of binary interaction, and some show no evidence for a luminous companion in their optical spectra. Here, we present multi-epoch radial velocity (RV) measurements for eight of these systems obtained with Magellan/MagE from 2018-2023. Five helium stars exhib…

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astro-ph.IM2026年9月25日

Selective state space model for photon energy estimation in microwave kinetic inductance detectors

Benjamin A. Mazin

Microwave Kinetic Inductance Detectors (MKIDs) are superconducting photon-counting detectors that measure the energy and arrival time of individual photons on large-format arrays. The standard energy estimator applies a coordinate transform followed by a Wiener optimal filter, optimal only for stationary noise, linear response, and energy-independent pulse shapes, assumptions that MKIDs structurally violate. We present Venom (Very Efficient Neural Optimal-filter for MKIDs), a selective state spa…

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astro-ph.HEastro-ph.SRgr-qc2026年9月25日

Mass and spin properties of black-hole mergers reveal formation in triples

Jakob Stegmann, Aleksandra Olejak

Deciphering the formation channels of the observed binary black hole mergers remains a central open problem in gravitational-wave astronomy. With hundreds of detections, the inferred distribution of masses and spins reveals a rich diversity which is difficult to reconcile with traditional formation scenarios from isolated binary stars or dense stellar environments. Here, we consider the large fraction of massive progenitor stars found in hierarchical triples and investigate black hole mergers dr…

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astro-ph.GAastro-ph.HEastro-ph.SRphysics.plasm-ph2026年9月25日

Saturation Mechanism of Cosmic Ray Streaming Instabilities with a Shell Distribution

Mohamad Shalaby, Rouven Lemmerz, Christoph Pfrommer

Cosmic rays (CRs) drive galactic winds and regulate galaxy growth while contributing to heating the central cooling plasma in dense galaxy clusters, making the nonlinear saturation of the instabilities that govern their transport a problem of central importance in astrophysics. Using fully kinetic particle-in-cell (PIC) simulations, we find that the streaming instability driven by CRs with a shell momentum distribution saturates through gyro-phase bunching around driven Alfvén waves. Fluid-PIC (…

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astro-ph.GAastro-ph.CO2026年9月25日

TRICEPS. I. Tracing cold gas, dust, and stars at sub-kpc scales in massive star-forming galaxies at z = 4-5

Federico Lelli, Lingrui Lin, Zhi-Yu Zhang, Cecilia Bacchini, Davide Bevacqua, Joe Bhangal, Marco Castellano, Carlos De Breuck et al.

We introduce the TRICEPS (Tracing Resolved Ionized Carbon Emission in Primeval Systems) survey. TRICEPS focuses on a sample of 16 massive galaxies at z = 4 - 5 with top-quality data: (i) ALMA band-7 observations of the [CII]-158 micron line, tracing the cold gas distribution and kinematics at spatial resolutions of about 0.1" (~0.8 kpc), (ii) ALMA maps of the rest-frame 160 micron continuum emission, tracing the dust distribution at similar spatial resolutions, (iii) multi-band JWST images from…

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astro-ph.GA2026年9月25日

Hidden in the Halo: New Diffuse Star Clusters in the M82 Starburst with JWST

Deepthi S. Prabhu, David J. Sand, Burcin Mutlu-Pakdil, Adam Smercina, Denija Crnojevic, Michael G. Jones, Paul Bennet, Amandine Doliva-Dolinsky et al.

Diffuse star clusters (DSCs) occupy a poorly explored region of the size-luminosity plane between classical globular clusters (GCs) and dwarf galaxies. Here we report the discovery of four faint DSCs in the halo of the nearby starburst galaxy M82 using archival JWST/NIRCam imaging. We resolve individual stars in all four systems, whose color-magnitude diagrams are consistent with predominantly old ($\sim10$ Gyr) stellar populations, based on comparison with isochrones. DSC 1 hosts a metal-poor p…

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astro-ph.SRastro-ph.EPastro-ph.HEphysics.plasm-ph2026年9月25日

Non-linear dynamo waves in magnetized shear flows: a candidate mechanism for the solar cycle

Uddipan Banik

Large-scale magnetic reversals in planets, stars, and accretion disks require a non-linear theory coupling the magnetic field to its sustaining flow. We derive exact non-linear solutions to incompressible magnetohydrodynamics in background rotational shear, with large-scale velocity and magnetic fields linear in position (affine form). They reveal a cyclic feedback between meridional circulation, shear, magnetic tension, induction, and the Coriolis force. The steady-circulation reversal orbit, o…

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astro-ph.GA2026年9月25日

A Self-Consistent Jeans Analysis of the Milky Way Rotation Curve

Yongjun Jiao, Francois Hammer, Istiak Akib, Yanbin Yang, Haifeng Wang

Jeans-based measurements of the Milky Way (MW) rotation curve (RC) have revealed a declining outer RC. The interpretation, however, depends sensitively on the tracer selection, the tracer density profile, gradient terms in the Jeans equation, and non-axisymmetric perturbations in the outer disk. We present a more self-consistent Jeans analysis of the MW RC and reassess whether the outer decline remains after a revised treatment of the main Jeans terms and their associated systematic uncertaintie…

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astro-ph.EPastro-ph.IM2026年9月25日

Tails and Trails: Comets and NEOs Survive Co-addition in Rubin Early Data Preview 2

Colin Orion Chandler, Joseph Murtagh, Ian Chow, Maxine West, A. Fraser Gillan, Peter S. Ferguson, Michael S. P. Kelley, Jacob A. Kurlander et al.

We identify effectively single-visit imaging hidden within the deep co-added images of the NSF-DOE Vera C. Rubin Observatory Early Data Preview 2 (EDP2). These shallow regions contain only one or two contributing visits, providing access to single-visit-depth imaging ahead of the full Data Preview 2 (DP2) release in late 2026. We develop a workflow to locate known small Solar System bodies in these data, using our Ponder orchestrator with the Sorcha survey simulator to predict their positions an…

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astro-ph.GA2026年9月25日

A Self-Consistent Jeans Analysis of the Milky Way Rotation Curve

Yongjun Jiao, Francois Hammer, Istiak Akib, Yanbin Yang, Haifeng Wang

Jeans-based measurements of the Milky Way (MW) rotation curve (RC) have revealed a declining outer RC. The interpretation, however, depends sensitively on the tracer selection, the tracer density profile, gradient terms in the Jeans equation, and non-axisymmetric perturbations in the outer disk. We present a more self-consistent Jeans analysis of the MW RC and reassess whether the outer decline remains after a revised treatment of the main Jeans terms and their associated systematic uncertaintie…

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astro-ph.GA2026年9月25日

Igniting Galaxy Formation in the Postreionization Universe, II: Nature versus Nurture

Jorge Moreno, Defne Aluç, Eisha López, Vivienne Wood, Emmanuel Santiago, Francisco J. Mercado, Caleb R. Choban, Coral Wheeler et al.

Although the ultraviolet background from reionization is thought to conspire against the smallest halos, some gas-rich halos in the post-reionization Universe still form stars. We ask which properties, environmental or intrinsic, determine ignition. Using the FIREbox cosmological volume, we compare recently-ignited halos to a mass- and gas-matched sample of gas-resolved starless halos at $z=2$--6. We test three families of "third axis" properties beyond $M_{\rm vir}$, $M_{\rm gas}$, and $z$: geo…

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astro-ph.GAastro-ph.EPastro-ph.SR2026年9月25日

The geometric origin of the thermal eccentricity law

Václav Pavlík

The distribution $f(e)=2e$ is commonly referred to as the `thermal eccentricity distribution' of Keplerian binaries. However, the result does not require thermal equilibrium, and its usual derivations obscure why the distribution is linear in eccentricity. We seek a simple geometrical interpretation of this result and its relation to more general eccentricity distributions. We consider bound Kepler orbits in a Euclidean space of dimension $D\geq2$, with a phase-space distribution depending only…

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astro-ph.EPastro-ph.IM2026年9月25日

Simulating the thermodynamics of gas, radiation, and multispecies dust: Method and applications to protoplanetary disks

Dhruv Muley, David Melon Fuksman, Prakruti Sudarshan, Alexandros Ziampras, Mario Flock

The thermodynamics of protoplanetary disks, governed by a complex interplay between gas, dust, and radiation, exerts a strong influence on their morphology and dynamics at both large and small scales. Historically, hydrodynamical simulations have treated thermodynamics with approximate prescriptions, such as local isothermality, parametrized $β$-cooling, and radiation hydrodynamics with gas-dust thermal equilibrium. However, a more comprehensive and self-consistent approach would more accurately…

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astro-ph.GA2026年9月25日

Breaking the Blend: A multi-tracer kinematic decomposition method for IFS data applied to disentangling the AGN outflow and circumnuclear ring in NGC 5728 with JWST

Oscar Veenema, Niranjan Thatte, Dimitra Rigopoulou, Richard I. Davies, Miguel Pereira-Santaella, Ismael García-Bernete, Almudena Alonso-Herrero, Anelise Audibert et al.

Integral field spectroscopy (IFS) of the central kiloparsecs of active galactic nuclei (AGN) reveals a mixture of spatially coincident emission from star-formation and AGN feedback exciting the interstellar medium. Disentangling these components remains a challenge, as most spectral tracers are affected by both processes, limiting robust interpretation of kinematics and energetics. We present a new framework for decomposing IFS data into distinct components on a spaxel-by-spaxel basis using a mu…

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astro-ph.SR2026年9月25日

Disc-mediated angular momentum transport resolves the mass-gain problem in rotating binaries

Sebastian Ljung, Avishai Gilkis, Sandro Tacchella

A large fraction of stars interact with a close companion during their lifetime, in which the transfer of mass and angular momentum shapes their evolution and final fate. Standard rotationally limited accretion models predict that accretors reach critical rotation after gaining only a small fraction of their mass, severely suppressing further accretion. This is in tension with observations of post-interaction systems that require substantial mass gain. We introduce a disc-mediated angular moment…

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astro-ph.IM2026年9月25日

Differential Double Blind Fourier Holography (diff-DBFH)

Oren Pedatzur, David T. Chuss

High-performance optical systems, including space telescopes, require wavefront-sensing and correction capabilities to achieve resolution near the diffraction limit. Existing wavefront-sensing approaches span a broad range of architectures, but many require dedicated interferometric hardware, rely on computationally intensive nonlinear or iterative reconstruction algorithms or provide only limited wavefront information. Focal-plane wavefront-sensing methods are particularly attractive because th…

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gr-qcastro-ph.HEhep-th2026年9月25日

The third law of black hole thermodynamics and the mass-to-charge ratio of scalar fields

Shahar Hod, Tsvi Piran

Kehle and Unger have recently shown that self-gravitating charged classical scalar fields can collapse to form extremal Reissner-Nordström (eRN) black holes in finite time, thus violating the third law of thermodynamics (TLT). Reall has subsequently proved that the formation of an eRN black hole in gravitational collapse is impossible if the mass-to-charge ratio of the field exceeds unity, $m/e\geq1$. In the present compact paper we conjecture, using quantum considerations, that the Reall bound…

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