研究動向

astro-ph.HE2026年9月23日

A Coherent Search for New Galactic Magnetars using Fermi/GBM and follow-up Swift/BAT: 7 Candidates and a Large Burst Catalog

Ariel Perera, Barak Zackay, Tejaswi Venumadhav

Galactic magnetars are a rare class of neutron stars with extreme magnetic fields, with only about 30 known sources. Their short hard X-ray and soft gamma-ray bursts provide an important channel for discovering magnetar activity. Wide-field instruments such as the Fermi Gamma-ray Burst Monitor (GBM) are well suited to detecting these bursts, but their broad localization uncertainties make it difficult to associate individual bursts with specific sources. Coded-aperture telescopes, in contrast, p…

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astro-ph.EP2026年9月23日

JWST and HST Confirm Transit Timing Variations for the Ultra-Hot Jupiter TOI-2109 b

Michael Greklek-McKeon, Julie Inglis, Nicole L. Wallack, Shreyas Vissapragada, Ian Wong, John R. T. Allen, Yayaati Chachan, Fei Dai et al.

Ultra-hot Jupiters are a rare yet valuable subset of exoplanets that can help elucidate both the internal properties of their host stars as well as the orbital evolution of close-in planets. An extreme among extremes, TOI-2109 b is a super-Jupiter ($1.347 \pm 0.047 R_{\rm Jup}$, $5.02 \pm 0.75 M_{\rm Jup}$) with the shortest orbital period (0.67247479 $\pm$ 0.00000028 days) and the fastest predicted orbital decay rate of any known giant planet. Previous observations hinted at a quadratic long-te…

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hep-phastro-ph.COastro-ph.GA2026年9月23日

The universe as a superconductor: How to search for a photon mass

Andrei Gruzinov, Anson Hook, Junwu Huang

We revisit the bounds on the photon mass when it arises from an Abelian Higgs mechanism rather than a Proca term. Because the higgs is necessarily millicharged and light, the phase of the theory (Meissner, vortex, or symmetry-restored) depends on the ambient magnetic field, so the photon mass an experiment measures depends on the environment it is performed in. We classify existing experiments by the phases in which they apply, in analogy with Type I and Type II superconductors. For Type I photo…

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astro-ph.GA2026年9月23日

Galaxies Below the Fundamental Metallicity Relation Are Morphologically Disturbed: Merian H$α$ Morphologies and DESI Metallicities

Abby Mintz, Jenny E. Greene, Shany Danieli, Erin Kado-Fong, Alexie Leauthaud, Jiaxuan Li, Yifei Luo, Annika H. G. Peter et al.

Empirical results have revealed a connection between a galaxy's metallicity, mass, and star formation rate, known as the fundamental metallicity relation (FMR), in which metallicity increases with stellar mass and decreases with SFR. Physical interpretations of the FMR suggest that actively star-forming galaxies are fueled by pristine gas, likely obtained via IGM accretion or minor mergers. Here we demonstrate the value of galaxy morphology as an additional axis in the FMR. Using medium-band ima…

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astro-ph.GA2026年9月23日

DIISC-VII: Linking Radial Gas Motions to Anomalously Low Metallicity Star-forming Regions in the XUV Disk of NGC 3344

Alejandro J. Olvera, Sanchayeeta Borthakur, Enrico M. Di Teodoro, Kanak Saha, Mansi Padave, Hansung B. Gim, Emmanuel Momjian

We present evidence connecting anomalously low-metallicity regions to radial gas inflows in the extended ultraviolet (XUV) disk of the galaxy NGC 3344. Anomalously low-metallicity H II regions are hypothesized to result from the accretion of metal-poor gas, but a direct link between gas flows and low metallicity gas has not been previously established. We use high-resolution H I-21cm imaging from the Very Large Array to trace neutral gas kinematics and multi-slit optical spectroscopy from the MM…

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astro-ph.IMastro-ph.GA2026年9月23日

EPIMETHEUS: Effective PSF inferred from mosaics

Pietro Benotto, Benedetta Vulcani, Vittoria Altomonte

Accurate knowledge of the point spread function (PSF) is essential for a wide range of astronomical applications, from astrometry to precision photometry. However, deriving a robust average effective PSF (ePSF) from astronomical mosaics is particularly challenging due to the superposition of exposures taken at different epochs, under different observing conditions, and with varying position angles (PAs). To address this issue, we present EPIMETHEUS, an open-source Python library designed to mana…

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hep-phastro-ph.HEhep-exhep-th2026年9月23日

Precise QCD Predictions for the Scotogenic Model at Colliders

Mohammed Boukidi, Camila Ramos, Richard Ruiz

Motivated by the anticipated data rates of the high-luminosity phase of the Large Hadron Collider, we report the first predictions up to next-to-leading order in quantum chromodynamics with parton-shower matching for the production and decay of scalars and heavy neutrinos from the Scotogenic model for neutrino masses and dark matter at $\sqrt{s}=14$ TeV and $\sqrt{s}=100$ TeV. We carry out our simulations using the \texttt{FeynRules}+\texttt{MadGraph5\_aMC@NLO}+\texttt{Pythia8} pipeline. As a by…

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astro-ph.EP2026年9月23日

Revealing the Shiny Nature of Lava Worlds: Small Planet Phase Curves with TESS

Brandon Park Coy, Michael Zhang, Fei Dai, Qiao Xue

Recent thermal emission observations suggest that `lava worlds'--Earth-sized exoplanets hot enough to melt their silicate surfaces--have atmospheres on a population-level. This evidence comes from measured dayside brightness temperatures much lower than expected for a dark, maximally hot bare rock. However, these results are degenerate between a thick atmosphere advecting heat to the planet's nightside or a high albedo reflecting incoming radiation. This degeneracy can be resolved through visibl…

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astro-ph.HEastro-ph.GAgr-qc2026年9月23日

Compact Object Mergers and Micro-Tidal Disruption Events: A Multi-Messenger Probe of Dense Stellar Environments

Konstantinos Kritos, Francesco Iacovelli, Rosalba Perna, Emanuele Berti

Dense stellar environments such as globular clusters and young massive clusters produce both compact-object mergers detectable in gravitational waves and tidal disruption events observable electromagnetically. We investigate compact-object mergers, tidal disruption events, and micro-tidal disruption events ($μ$TDEs) in these environments using rapid Monte Carlo star-cluster simulations with the Rapster code, extended with a unified treatment of neutron-star (NS) and black-hole (BH) spin evolutio…

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astro-ph.GA2026年9月23日

Euclid Quick Data Release (Q1): Disc breaks highlight the structural evolution of galaxies through time

Euclid Collaboration, P. M. Sanchez-Alarcon, J. Román, S. Comeron, J. H. Knapen, M. Huertas-Company, F. Buitrago, M. Montes et al.

Changes in the slope of the radial surface brightness profiles of disc galaxies, or disc breaks, encode valuable information about the processes driving disc formation and growth. Until now, due to the resolution and depth required, statistical studies of break types have been limited mostly to the local Universe. We aim to study the structural properties and redshift evolution of disc breaks in a large and statistically representative sample of galaxies out to redshift z=1 using the superb dept…

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astro-ph.GAastro-ph.CO2026年9月23日

The First Blind Survey of Intervening NaI Absorbers: Incidence and Cosmic Evolution with DESI

Abhijeet Anand, Sowgat Muzahid

We present the first blind statistical survey of intervening NaI absorbers over the last $\simeq3$~Gyr using quasar spectra from the Dark Energy Spectroscopic Instrument Data Release~1. We identify 3636 NaI D doublets at $0.01\lesssim z_{\rm abs}\lesssim0.27$ along 214,035 quasar sightlines. We quantify the survey selection function through end-to-end injection--recovery tests and estimate the residual contamination from visual inspection. The completeness reaches 50% at a rest-equivalent width…

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astro-ph.GA2026年9月23日

The BRIDGE Survey. I. Metallicities and Physical Properties of Gas Probing the Circumgalactic Medium at Cosmic Noon

Saloni Deepak, Nicolas Lehner, J. Christopher Howk, John O'Meara, Celine Peroux, J. Xavier Prochaska

We present BRIDGE-I, a metallicity survey of \HI-selected absorbers probing ``CGM-like'' gas ($16.4\leq \log N_{\rm HI} 2.2$ ($-2.02$). This plateau is driven by the most diffuse absorbers ($16.4\leq \log N_{\rm HI} 2.2$, no absorber falls below $[\rm{X/H}]=-3.5$, indicating no pristine CGM-like gas at Cosmic Noon. Absorbers in BRIDGE-I trace overdensities of $400\lesssim δ_b\lesssim2200$, higher than at $z>2.2$. Mean $N_{\rm HI}$ differs by a factor of 400 across absorber types, but mean total…

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astro-ph.GA2026年9月23日

Comparing phylogenetic trees of stars with spectral graph distances

Theosamuele Signor, Matias Neto, Paula Jofré, Sara Vitali, Xia Hua, Patricia B. Tissera, Claudia Aguilera-Gómez, Payel Das et al.

Phylogenetic trees offer a hierarchical representation of chemical similarities among stars, from which their evolutionary histories can, in principle, be reconstructed. Simulation-based work suggests that phylogenetic trees built under different chemical evolution scenarios carry distinguishable structural imprints, but whether existing methods can detect this signal in practice is unclear. We evaluate distance measures, both classical tree-based and graph-theoretical, for comparing phylogeneti…

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hep-phastro-ph.HE2026年9月23日

Resonant neutrino flavor conversion within dark matter spikes

P. S. Bhupal Dev, Elisa Gaido, Alejandro Ibarra, Yago Porto

We investigate how neutrino--dark matter (DM) interactions modify the flavor composition of high-energy neutrinos from active galactic nuclei (AGNs). Coherent forward scattering in a DM spike around the central supermassive black hole can generate a flavor-dependent potential, inducing flavor conversion as the neutrinos escape. We calculate the flavor composition at Earth for pion-decay and muon-damped sources and find substantial departures from vacuum-oscillation expectations. At neutrino ener…

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physics.space-phastro-ph.SRphysics.plasm-ph2026年9月23日

First Observation of a Polar Coronal Hole-like Fast Solar Wind Stream in the Sub-Alfvénic Solar Corona: an Analysis of Turbulence Properties

Riddhi Bandyopadhyay, Sujan Prasad Gautam, William H. Matthaeus, Yeimy J. Rivera, Samuel T. Badman

Parker Solar Probe, near its 23rd perihelion in March 2025, sampled an extended interval of sub-Alfvénic solar wind likely originating from a large equatorial coronal hole. At heliocentric distances of approximately 10 solar radii, with speed mostly above 400 km/s, this interval is a first example of ``polar coronal hole-like (PCH-l) fast" solar wind observed in the sub-Alfvénic solar corona. We characterize the turbulence properties of this unique interval using Parker Solar Probe measurements.…

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astro-ph.GA2026年9月23日

JWST Observations of Starbursts: The motion of dust - PAH kinematics of M82 and NGC 253 with JWST/MIRI spectroscopy

Fergus R. Donnan, Karin Sandstrom, Alberto D. Bolatto, Bruce T. Draine, Sara E. Duval, Ralf S. Klessen, Elisabeth A. C. Mills, Helena M. Richie et al.

We present an analysis of dust kinematics in the local starburst galaxies M82 (NGC 3034) and NGC 253 using Polycyclic Aromatic Hydrocarbon (PAH) features observed with JWST/MIRI spectroscopy. We are able to produce high-quality velocity maps of the 5.2 $μ$m, 6.2 $μ$m, and 11.3 $μ$m PAH features, as well as numerous lines of molecular gas via H$_2$ rotational transitions and ionized gas from [NeII] and H recombination lines. Given the field of view and inclination, we trace a rotating disk in M82…

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astro-ph.GA2026年9月23日

The molecular gas of four ram pressure stripped galaxies in the core of the Hydra I cluster

Clara C. de la Casa, Kelley M. Hess, Nikki Zabel, Emanuela Pompei, Yara L. Jaffé, Nazir Makda, Julia Healy, Johanna Hartke et al.

We present new CO(1-0) measurements from ALMA and new HI measurements from MeerKAT in four ram pressure stripped (RPS) galaxies in the core of the Hydra I cluster: NGC 3312, NGC 3314a, NGC 3314b and LEDA 753342. These deep data, with compatible spatial resolution in CO and HI ($\sim15''$, $\sim$4 kpc), help increase the low statistics of galaxies observed in CO at extreme infall stage for probing how molecular and atomic gas behave under high ICM pressures. We studied the cold gas morphologies o…

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astro-ph.SRcs.LGphysics.data-anphysics.space-ph2026年9月23日

PROSWIN: Probabilistic Solar Wind Speed Forecasting Using Deep Distributional Regression From Solar Images

Daniel Collin, Yuri Shprits, Luca Chiarabini, Stefan J. Hofmeister, Nadja Klein, Guillermo Gallego

Accurately predicting fast solar wind conditions is challenging, as uncertainties are large and unquantified by traditional single-value prediction models. In particular, the risks of high-speed solar wind streams (HSSs), which can cause damage to technological infrastructure, cannot be reliably assessed without probabilistic forecasts. We present PROSWIN, a probabilistic machine learning model that forecasts the hourly solar wind speed (SWS) at Earth with a four-day lead time. The approach comb…

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astro-ph.EP2026年9月23日

Characterization of Planetary Systems with Astrometry

Gisela N. Ortiz-Leon

Astrometry is the oldest method used to search for extrasolar planets. This technique provides key information about a planetary system, like the true mass of planets and its three-dimensional orbital architecture. Nowadays, the space-based mission Gaia, on one hand, and ground-based interferometry at infrared and radio wavelengths, on the other hand, can achieve astrometric accuracies of tens of micro-arseconds. Thanks to this unprecedented level of accuracy, the number of astrometrically disco…

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astro-ph.GAastro-ph.SR2026年9月23日

Globular cluster candidates uncovered by VVVX and MUSE

P. Rodríguez Cuevas, B. Dias, D. Minniti, E. Garro

The Milky Way has about 220 cataloged globular clusters. This number is far smaller than what is found in a similar galaxy such as Andromeda, which has about 600 globular clusters. Two possible reasons for this large difference might be observational bias and cluster dissolution. The infrared photometric survey VISTA Variables in the Via Lactea Extended has discovered many globular cluster candidates toward the Galactic bulge that need confirmation. We confirm the globular cluster nature of four…

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astro-ph.GA2026年9月23日

Misaligned tidal tails in open clusters: a signature of the local spiral arm resonance

Andrés E. Piatti

Tidal tails of open clusters are traditionally expected to align with their orbital motion due to Galactic shear. However, recent observations suggest that a significant population of clusters exhibits misaligned tails, the origin of which remains poorly understood. I investigate the structural properties of tidal tails for a sample of 155 nearby open clusters within 1 kpc of the Sun to characterize the influence of non-axisymmetric Galactic perturbers on stellar stripping geometry.Using high-pr…

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astro-ph.HEhep-ph2026年9月23日

Dark-matter relay for ultra-high-energy cosmic rays

Mikhail Sekretov

Astrophysical sources of ultra-high-energy cosmic rays (UHECRs) remain unidentified, and no nearby cosmic accelerators are established even for the highest-energy events. In addition, puzzling correlations of a fraction of UHECR flux with distant blazars were found by HiRes and, recently, Telescope Array experiments. Here we propose that dark matter can provide a mechanism to effectively transfer UHECRs from distant sources: dark-matter particles are boosted by UHECRs near the source and pass th…

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astro-ph.COastro-ph.IM2026年9月23日

Data-driven Galaxy Population Prior for Photometric Redshifts

Nikolas Frediani, Daniel Gruen, Luca Tortorelli, Jamie McCullough

Stage-IV cosmological surveys rely on well-characterised photometric redshift distributions for constraining cosmological models, yet the projected weak lensing requirements are about an order of magnitude more accurate than current state-of-the-art methods. Any photometric redshift inference depends - explicitly or implicitly - on a prior over galaxy SEDs, luminosities, and redshifts. In this paper, we develop a purely data-driven approach for modelling the galaxy population prior based on lear…

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astro-ph.IM2026年9月23日

The second Little UV Camera (LUVCam2) mission

Emily Hu, Suresh Sivanandam, Albert Lau, Coby Silayan, Mark Barnet, Shaojie Chen, Gavin Hay, Nadim Hatoum et al.

The second Little UltraViolet Camera (LUVCam2) is a 80mm-diameter dual UV-optical space telescope that will observe the UV flares around low-mass stars, with planned flight as a $\sim$1.4U payload aboard the 3U CubeSat BRNOsat in late 2027. We present the concept of operations, full system architecture, optomechanical, and electrical design for LUVCam2. LUVCam2 is the second technology demonstration for the LUVCam electronics board, with the first LUVCam (LUVCam1) still operating in low-Earth or…

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astro-ph.EP2026年9月23日

High-resolution optical spectroscopy reveals the distinctive volatile composition of the interstellar comet 3I/ATLAS

K. Aravind, E. Jehin, C. Opitom, J. Manfroid, D. Hutsemékers, D. Bodewits, M. Bannister, R. C. Dorsey et al.

Comets preserve volatile material from the early stages of planetary-system formation. The discovery of the interstellar comet 3I/ATLAS enables a direct comparison between a comet formed around another star and comets in the Solar System. We characterise the coma composition of 3I/ATLAS across perihelion using homogeneous high-resolution near-UV and optical spectroscopy with UVES on the ESO Very Large Telescope, from August 2025 (r$_h$=3.14 au) pre-perihelion to February 2026 (r$_h$=4.34 au) pos…

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astro-ph.HE2026年9月23日

Self-consistent modeling of energy-dependent synchrotron polarization in blazars with application to Mrk 421

Frederike Apel, Motseothata Tisang, Victor Barbosa Martins, Xavier Rodrigues, Markus Böttcher, Anna Franckowiak

Observations of black hole jets closely aligned with our line of sight, known as blazars, have revealed that their X-ray emission can be significantly more polarized than in the optical bands. This chromatic polarization is often attributed to an energy-stratified jet. In blazars with X-ray emission dominated by electron synchrotron, the pitch angle between the magnetic field lines and electron velocity might also affect the frequency dependence of the polarization degree, but this effect is gen…

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astro-ph.SR2026年9月22日

Catalogue of Solar Radio Bursts Detected by the LOFAR LV614 Station at the Irbene Observatory during Solar Cycle 25

Jānis Šteinbergs, Dmitrii Kolotkov, Valery M. Nakariakov, Vladislavs Bezrukovs, Pietro Zucca, Jānis Kaminskis

A catalogue (https://doi.org/10.5281/zenodo.20157853) of solar radio bursts detected with the LV614 LOFAR station at the Irbene Observatory, Latvia, in the stand-alone mode from June 2022 to August 2025 in the 29-60 MHz frequency range is presented. Observations were conducted with the weekly cadence, one-second time resolution, and 0.195 MHz spectral resolution. The cumulative duration of the observation was 1125.2 h. For all analysed observations, bandpass calibration was applied using Cassiop…

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astro-ph.SR2026年9月22日

V844 Herculis: An Exceptional Intermediate Polar Hiding in an Ordinary Dwarf Nova

Anousha Greiveldinger, Peter Garnavich, Colin Littlefield, Mark R. Kennedy, Paula Szkody, Jordan Tweddale, Mark Whittle, Teófilo Arranz et al.

We present time-series spectroscopy of the SU UMa-type dwarf nova V844 Her during quiescence. We discover high-velocity Balmer and He I emission features modulated at a period of 29.3$\pm$0.1 minutes. The spectroscopic periodicity is identical to the photometric period detected only during superoutbursts. Interpreting this as the result of magnetic accretion onto the white dwarf, we identify V844 Her as an intermediate polar (IP). The spin period of the white dwarf is most likely to be 29.3 minu…

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astro-ph.GA2026年9月22日

Exploring the influence of reionisation-era galaxies on their local intergalactic medium using the Sherwood-Relics simulations

Hamish Anderson, Laura C. Keating, Luke Conaboy, Xiangyu Jin, James S. Bolton, Ewald Puchwein

Recent surveys have detected excess flux in the Lyman-$α$ forest of quasar spectra several Mpc from high-redshift line-emitting galaxies, indicating a correlation between intergalactic medium (IGM) transmission and reionisation-era galaxies. We examine the galaxy-IGM connection using the Sherwood-Relics simulation suite, a set of hybrid radiation-hydrodynamic simulations that model the IGM at high redshift. We simulate the Lyman-$α$ forest and a population of mock [OIII] emitters using the surve…

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astro-ph.COastro-ph.GA2026年9月22日

Bayesian Galaxy Asymmetry

Mathieu Perron-Cormier, Kristine Spekkens, Nathan Deg, Lawrence M. Widrow, Marcin Glowacki

Galaxy asymmetry is an efficient way to characterize galaxy morphology in atomic hydrogen 21 cm emission detections. We propose a novel Bayesian approach to calculate the probability of an underlying squared differences asymmetry in a noisy detection. This approach has a number of advantages, including the recovery of low asymmetry values where prior noise corrections failed. More importantly, our approach provides robust uncertainties on the asymmetry, enabling a wide variety of statistical stu…

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