Current date: 2026-11-11
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Created/updated limit: 2026-11-04 (7 days ago)
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Number of records retrieved: 857
Keyword score statistics
score 12 -- 1 abstracts
score 10 -- 2 abstracts
score 8 -- 1 abstracts
score 7 -- 2 abstracts
score 6 -- 1 abstracts
score 5 -- 6 abstracts
score 4 -- 3 abstracts
score 3 -- 12 abstracts
score 2 -- 20 abstracts
in total -- 48 abstracts
Articles that appeared on 2026-11-11
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[abstract 1 / 48] Wow! (score: 12)
- Title: Unveiling the Extreme Universe with Recent IACT DiscoveriesAuthors: R. López-Coto,Comments: Gamma 2026 proceedingSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Very-high-energy (VHE, $E \gtrsim 50$\,GeV) $γ$-ray astronomy has evolved into an indispensable pillar of modern astroparticle physics, offering a direct view of non-thermal particle acceleration, cosmic-ray origins, and fundamental physics. Ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs) have driven this revolution over the past two decades. In this plenary review, presented at the 9th Heidelberg International Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2026), I provide a synthesis of recent breakthrough physics discoveries achieved by current IACT arrays (H.E.S.S., MAGIC, and VERITAS) alongside early scientific achievements from the Large-Sized Telescope prototype (LST-1) of the Cherenkov Telescope Array Observatory (CTAO). Key highlights include the definitive establishment of recurrent novae as transient cosmic-ray proton accelerators via RS Ophiuchi; spatially resolved multi-TeV emission from the RELATIVISTIC JET termination shocks of microQUASARs; the discovery of a 20 TeV pulsed radiation component from the Vela pulsar, challenging established MAGNETospheric emission paradigms; precision measurements of the Galactic Center diffuse ridge spectrum favoring a high-energy cutoff; the detection of distant flat-spectrum radio QUASARs at $z \sim 1$ (OP 313 and PKS 0346-27), providing tight cosmological constraints on the Extragalactic Background Light; multi-wavelength afterglow detections of $γ$-ray bursts including GRB 221009A; and world-leading joint indirect DARK MATTER limits from dwarf spheroidal galaxy and Galactic Center halo analyses. Together with algorithmic advances in deep learning reconstruction and the ongoing construction of CTAO, these milestones demonstrate the enduring vitality and future trajectory of ground-based $γ$-ray astrophysics.
[abstract 2 / 48] Wow! (score: 10) - Title: The Ordinary Days of Extraordinary Blazar 3C 454.3Authors: Sajeesh George, P N Naseef Mohammed, Aminabi Thekkoth, Vaidehi S. Paliya, C D Ravikumar,Comments:Subjects: astro-ph.HECreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
The BLAZAR 3C 454.3 (z = 0.859) is one of the brightest and most variable flat-spectrum radio QUASARs in the sky. Here, we present a multi-wavelength analysis of this enigmatic object in its quiescent states during June 2022 and May 2023 coincident with its first X-ray polarimetric and hard X-ray observations with International X-ray Polarimetric Explorer (IXPE) and Nuclear Spectroscopic Telescope Array (NUSTAR). Though no X-ray POLARIZATION was detected, NUSTAR detected the source on all occasions during this period. We generated five broadband spectral energy distributions (SEDs)of the BLAZAR using quasi-simultaneous observations taken with the FERMI-Large Area Telescope, NUSTAR, and Neil Gehrels SWIFT Observatory. The hard X-ray flux measured by NUSTAR exhibited mild flux variations. The SEDs were modeled with a one-zone leptonic emission framework using the JetSet package. The optical-ultraviolet spectrum of 3C 454.3 revealed an upturn which we reproduced with the standard accretion disk model. The X-ray to gamma-ray spectrum of 3C 454 was found to be well explained by the external Compton (EC) process with the seed photons provided by the BLR and accretion disk. These results provide intriguing clues about the multi-wavelength behavior of 3C 454.3 during its quiescent activity state.
[abstract 3 / 48] Wow! (score: 10) - Title: Log-normal behavior of Optical Polarization in a sample of Blazars: Evidence for Multiplicative Magneto-hydrodynamic Processes in Relativistic JetsAuthors: A. Singh, A. Tolamatti, K. K. Singh, A. C. Gupta, B. Ghosal, K. K. Yadav,Comments: Accepted for Publication in the Journal of High Energy AstrophysicsSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Optical SYNCHROTRON POLARIZATION is one of the most direct probes of the MAGNETic-field structure and particle-acceleration processes in the RELATIVISTIC JETs of BLAZARs. Although long-term optical flux variability is often attributed to multiplicative stochastic processes because of its log-normal behavior, but the physical origin of optical POLARIZATION variability remains less understood. In this study, we investigate the long-term optical flux and POLARIZATION variability of a sample of BLAZARs using nearly a decade of photo-polarimetric observations from the Steward Observatory. We find that, like the optical flux, the optical degree of POLARIZATION is generally well described by a log-normal distribution and shows an approximately linear relationship between its variability amplitude and mean value. We interpret this behavior within a MAGNETo-hydrodynamic (MHD) framework in which the MAGNETic-field undergoes repeated stochastic changes driven by shocks, turbulence, velocity shear, and large-scale JET dynamics. The cumulative effect of these processes can naturally generate multiplicative variability, leaving similar statistical signatures in both the SYNCHROTRON flux and the degree of POLARIZATION. Our results provide new observational evidence that the long-term statistical behavior of optical flux and POLARIZATION may arise from a common set of MHD processes associated with MAGNETic-field evolution.
[abstract 4 / 48] Wow! (score: 8) - Title: One year of broadband radio monitoring of the enigmatic transient GRB 250702B reveals the evolution of the RELATIVISTIC JETAuthors: A. J. Goodwin, James C. A. Miller-Jones, Itai Sfaradi, Andrew Mummery, Raffaella Margutti, Tanmoy Laskar, K. D. Alexander, Yuhan Yao, Arvind Balasubramanian, G. C. Anupama, Edo Berger, Varun Bhalerao, Yvette Cendes, Ryan Chornock, C. T. Christy, D. Eappachen, Tarraneh Eftekhari, Miguel Pérez-Torres, Enrico Ramirez-Ruiz, D. K. Sahu, Sjoert van Velzen,Comments: 29 pages, 15 figures, accepted by MNRAS. All data in Table D1 available in machine readable format upon requestSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We present an extensive radio monitoring campaign of the unique extragalactic transient GRB 250702B, associated with unprecedentedly long duration gamma-ray emission, lasting over 3\,hr. Our observations span 0.65-233 GHz from 6-356 d (observer frame) post-discovery. The radio emission shows a smoothly evolving peaked SYNCHROTRON spectrum consistent with an adiabatic shock expanding into a stratified ambient medium ($n_e\propto R^{-k}$; $k= 1.5-2$). We detect significant variability in the low frequency ($\leq3$ GHz) light curves which we interpret as interstellar scintillation, placing an approximate bound on the blast wave image size of $1.2\times10^{16}\lesssim R_{\perp} \lesssim 5\times10^{17}$ cm. The temporal evolution of the flux density and critical SYNCHROTRON frequencies suggest the shock that powers the radio emission is potentially a wide-angle $θ_j\gtrsim15$ deg, low Lorentz factor ($Γ\lesssim10$) JET, or a narrow $θ_j\lesssim2$ deg highly RELATIVISTIC JET. A narrow JET is expected for a stellar-mass BLACK HOLE engine, such as a helium star merger, and the beaming-corrected kinetic energy in this scenario is consistent with the known distribution for long GRBs ($E_K\sim10^{51}$ erg). The wide-angle JET scenario would instead require a progenitor involving prolonged accretion. We derive and show an intermediate or stellar-mass BLACK HOLE tidal disruption event are viable possibilities. The beaming-corrected kinetic energy in this scenario is on the low end of the known distribution for RELATIVISTIC SMBH TDEs ($E_K\sim10^{50}$ erg). We disfavour an SMBH TDE due to lack of compatibility with the observed timescales. The detection of a JET shut off within the next year would favour a WD-IMBH TDE due to the shorter theoretical duration of super-Eddington accretion than the main-sequence TDE channels.
[abstract 5 / 48] Wow! (score: 7) - Title: Gamma-Ray Modes in a Transitional PulsarAuthors: Maksat Satybaldiev, Manuel Linares,Comments: 12 pages, 4 figures, 2 tables. Published in the Astrophysical Journal LettersSubjects: astro-ph.HECreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
Transitional millisecond pulsars (tMSPs) exhibit a unique subluminous disk state, at the crossroads between accretion and rotation power, where they switch between two distinct X-ray modes. We present the discovery of gamma-ray modes in PSR J1023+0038, the first confirmed tMSP, from stacking FERMI-LAT data during the modes (which we identify using simultaneous X-ray observations). Surprisingly, we find that gamma rays and X-rays are anticorrelated during this mode switching: the gamma-ray flux is higher in the X-ray low mode, and vice versa. This contradicts the state-of-the-art model, which predicts bright gamma rays only in the X-ray high mode, from the interaction between the pulsar wind and surrounding disk via SYNCHROTRON and inverse Compton processes. Because the pulsar wind is likely absent in the gamma-ray high (X-ray low) mode, which is also brighter in the radio band, we suggest that JET emission may be dominant in GeV gamma rays. We also discuss an alternative interpretation where the gamma-ray high mode is powered by self-SYNCHROTRON Compton emission in the propeller state.
[abstract 6 / 48] Wow! (score: 7) - Title: Flux Variation of the Crab Pulsar Observed Using FERMI LAT and NUSTARAuthors: Koothodil Abhijith Augustine, Hsiang-Kuang Chang,Comments: 12 pages reading, rest of the pages are references. 3 figuresSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
The flux of pulsed emission from the Crab pulsar, just like most of other pulsars, is considered to be steady over time scales much larger than the pulsation period, except for a smooth, secular decrease related to the aging of pulsars. Such a steady assumption prevails in all theoretical investigations of pulsar emission models. However, here we report the discovery of stochastic fluctuation in the flux and photon index of the Crab pulsar gamma-ray and X-ray emissions utilizing archival data of FERMI LAT (0.1 -- 100 GeV, spanning 17 years) and of NUSTAR (3.0 -- 79.0 keV, spanning 13 years) observations. The origin of such fluctuation is intriguing. It might be related to possible configuration adjustment of MAGNETic fields in neutron stars' superconducting and superfluid interiors.
[abstract 7 / 48] Yes (score: 6) - Title: Giant Radio Galaxies from the Third Data Release of the LOFAR Two-metre Sky Survey (LoTSS-DR3): Physical Characteristics and EnvironmentsAuthors: Souvik Manik, Netai Bhukta, Sabyasachi Pal, Sushanta K. Mondal,Comments: 67 pages, 10 figures, 3 tablesSubjects: astro-ph.GACreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
Giant RADIO GALAXies (GRGs) are radio-loud ACTIVE GALACTIC NUCLEi (AGN) with projected linear sizes exceeding 0.7 Mpc, offering insights into the evolution of large-scale radio JETs and their environments. We present 2333 GRGs from the LOFAR Two-metre Sky Survey Data Release 3 (LoTSS-DR3), with projected sizes of 0.7-2.9 Mpc, redshifts of $0.126 \leq z \leq 3.517$, and 150-MHz radio luminosities of $1.72 \times 10^{24}$-$3.04 \times 10^{28}$ W Hz$^{-1}$. Of these, 726 ($\sim 31\%$) lie at $z \geq 1$. We investigate their radio properties, lobe energetics, equipartition pressures, BLACK HOLE masses, mid-infrared colours, and environments. Equipartition pressure decreases with increasing projected size, consistent with declining lobe energy density as radio structures expand, while its positive correlation with redshift persists after controlling for radio power and projected size. WISE colours highlight the diversity of the host-galaxy population, with approximately 75% of sources with available photometry falling within the empirical AGN/HERG region. For BCG-hosted GRGs, physical projected size shows no significant dependence on cluster mass. Although the normalized projected half-size, $D/(2r_{500})$, decreases with increasing cluster mass, this trend is consistent with the expected self-similar scaling of cluster radius rather than an independent suppression of radio-source growth in massive clusters. The substantial high-redshift population provides an opportunity to investigate GRGs at early cosmic epochs, although surface-brightness dimming and inverse-Compton losses against the cosmic microwave background can limit their detectability.
[abstract 8 / 48] Yes (score: 5) - Title: Nuclear Millimeter Continuum Emission in Radio-Quiet Active Galactic Nuclei: an ALMA Spectral and Variability StudyAuthors: Sophie M. Venselaar, Claudio Ricci, Yoshiyuki Inoue, Chin-Shin Chang, Akihiro Doi, Noemi Barnier, Taiki Kawamuro, Susanne Aalto, Momoka Hamamoto, Elena Shablovinskaya, Ezequiel Treister,Comments: Accepted for publication in The Astrophysical Journal (ApJ)Subjects: astro-ph.HE astro-ph.GACreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
Unresolved millimeter (mm) emission is observed in radio-quiet (RQ) Active Galactic Nuclei (AGN), but its physical origin remains debated. Self-absorbed SYNCHROTRON emission from the compact X-ray corona is one of the leading candidates. Previous support for this coronal SYNCHROTRON origin has mainly been based on variability and spectral indices in a few RQ AGN, with a lack of (quasi-)simultaneous broadband data for larger samples. We present Atacama Large Millimeter/sub-millimeter Array (ALMA) observations of nine nearby ($z \sim 0.008-0.064$) RQ AGN, obtained quasi-simultaneously at 100, 145, and 233 GHz. Based on power-law fits to the spectral energy distributions, we measure millimeter spectral indices ranging from $-0.05^{+0.09}_{-0.09}$ to $0.88^{+0.12}_{-0.11}$. Furthermore, across two 100 GHz observing epochs per source, separated by $4-11$ days, we detect flux density variability of $30-56$% (>$3σ$ significance level) in three out of nine sources. Spectral slopes alone are insufficient to constrain the origin of the millimeter emission; however, the observed short-timescale variability and inferred brightness temperature values are consistent with a non-thermal emission mechanism arising from a compact emitting region with a size of $R_{\rm mm}< 10^3 - 10^4 R_{\rm g}$, such as the corona or a compact JET. Furthermore, we find a clear correlation between the 100/233 GHz and X-ray flux in our sample, and establish a new linear correlation between 145 GHz and X-ray emission.
[abstract 9 / 48] Yes (score: 5) - Title: SS 433 Eastern Jet Turbulence Revealed by Spatially-Resolved IXPE Data AnalysisAuthors: Ningyue Fan, Jack T. Dinsmore, Roger W. Romani,Comments: 10 pages, 4 figures and 1 table. Accepted for publication in ApJSubjects: astro-ph.HECreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
The extended X-ray JET (EXJ) of SS 433/W50 shows hard X-ray and very-high-energy gamma-ray emission, indicating strong particle acceleration, likely sensitive to the EXJ MAGNETic field structure and turbulence. To study this field, we re-analyze the 2023 Imaging X-ray Polarimetry Explorer (IXPE) observation of the eastern EXJ using the publicly available POLARIZATION fitting package LeakageLib. Compared with standard PCUBE and spectropolarimetric analyses, this approach improves the POLARIZATION constraints and enables spatially resolved POLARIZATION measurements. Dividing the EXJ into head, spine, and sheath regions with independent POLARIZATION properties, we find significant (>3 sigma) improvement over a single-zone model. The sheath exhibits lower POLARIZATION than the head and spine, while the electric vector position angles are consistent across all regions, indicating MAGNETic fields aligned with the JET axis. The measurements imply enhanced MAGNETic turbulence at the JET boundary, potentially driven by Kelvin-Helmholtz instabilities.
[abstract 10 / 48] Yes (score: 5) - Title: The Edge of the Warm Corona in Active Galactic NucleiAuthors: Parikshit Partha Biswas, Agata Różańska, Debora Lančová, Dominik Gronkiewicz, Rafał Wojaczyński, Andrzej Zdziarski, Stefano Bianchi,Comments: 14 pages, 12 figures, submitted to ApJSubjects: astro-ph.HE astro-ph.GACreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
A model of warm, dissipative corona on top of an accretion disk is investigated, to explain the soft X-ray excess (SXE) emission observed in ACTIVE GALACTIC NUCLEi (AGN). The final ray-traced spectrum, computed through photoionization code with Comptonization, accounts for both: emitted and reflected components. As a result, the strength of the SXE depends on the radial extend of the warm corona, i.e., its outer edge. We show that the radial transition from warm corona to disk atmosphere is governed by line cooling. By moving away from a central BLACK HOLE Compton cooling is gradually replaced by line cooling, and the temperature drops sharply in vertical direction at a narrow iron ionization front, where iron ions Fe \textsc{xxv}--Fe \textsc{xxvi} recombine to Fe \textsc{xvii}. Notably, this transition takes place at a particular value of internal heating $\approx 1.6 \times 10^{-23}$ erg cm$^{3}$ s$^{-1}$, regardless of the Eddington ratio. We show, that at the given metal abundance, the SXE emitting area is larger for a higher accretion rate, in agreement with recent findings in changing look AGN. The overall emission spectrum from a warm corona is featureless, and the only iron K$_α$ line comes from a reflection. The line is stronger and more gravitationally distorted for a lower accretion rate, which is a direct result of the size of the warm corona. Furthermore, by increasing the iron abundance, the iron ionization front moves closer towards BLACK HOLE, and a stronger iron line complex is emitted locally.
[abstract 11 / 48] Yes (score: 5) - Title: Early X-ray emission as an observational diagnostic of GAMMA-RAY BURST progenitorsAuthors: Annarita Ierardi, Alessio Mei, Gor Oganesyan, Stefano Ascenzi, Samuele Ronchini, Marica Branchesi, Biswajit Banerjee, Maria Edvige Ravasio,Comments: Submitted to A&ASubjects: astro-ph.HECreated: 2026-11-06; Updated: 2026-11-11; Datestamp: 2026-11-11
Identifying the progenitors of GAMMA-RAY BURSTs (GRBs) from the properties of their early high-energy emission detected by wide-field satellites is crucial for advancing our understanding of GRB physics and for multi-messenger astronomy. Current classification methods, which rely primarily on prompt emission properties, exhibit large scatter and are challenged by recently detected events. In this Letter, we propose a new method to classify GRB progenitors using their early X-ray emission, which is detectable by current wide-field X-ray monitors. We performed a systematic time-resolved spectral analysis of the X-ray steep decay phase for a sample of 23 collapsar-driven GRB candidates detected by the Neil Gehrels SWIFT Observatory. We fitted the spectra over the $0.3 - 150 \, \rm keV$ energy range using both a physical SYNCHROTRON model and the empirical Band function, allowing us to constrain the spectral peak energy and the bolometric flux. We find a correlation between the rest-frame SYNCHROTRON cooling frequency, $ν_{c,z}$, and the isotropic-equivalent luminosity, $L_{\rm iso}$, that is clearly separated from the $ν_{c,z} - L_{\rm iso}$ relation followed by merger-driven GRB candidates. A similarly distinct separation is found in the correlation between the rest-frame peak energy, $E_{p,z}$, and $L_{\rm iso}$ obtained with the Band model. Finally, we provide a prescription for classifying fast X-ray transients detected by the Wide-field X-ray Telescope aboard the Einstein Probe mission, as its narrow energy range ($0.5 - 4 \, \rm keV$) limits spectral modelling to a simple power law. We show that the photon index and X-ray luminosity of the steep decay spectra clearly separate collapsar- and merger-driven candidate events, making them powerful diagnostics of GRB progenitors.
[abstract 12 / 48] Yes (score: 5) - Title: Detectability of Seyfert galaxies in point-source and stacking searches with a global network of neutrino telescopesAuthors: Lena Saurenhaus, Francesca Capel, Foteini Oikonomou,Comments: 16 pages, 9 figuresSubjects: astro-ph.HECreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
Recent evidence for high-energy neutrino emission from NGC 1068 and other nearby Seyfert galaxies suggests that ACTIVE GALACTIC NUCLEi (AGNs) may constitute a class of astrophysical neutrino sources. Using a physically motivated neutrino emission model based on stochastic particle acceleration in MAGNETized AGN coronae, we investigate the detection prospects of X-ray-bright Seyfert galaxies with a detector network comprising IceCube, Baikal-GVD, KM3NeT/ARCA, and P-ONE. We find that the Circinus Galaxy is the most promising point-source target in the Southern sky and will be detected at the 5$σ$ level by 2038 at the latest, provided that the Seyfert population accounts for the diffuse astrophysical neutrino flux up to 100 TeV and Circinus is at least as efficient a neutrino emitter as the average source in the population. Individual detections of other nearby Seyferts are expected to remain challenging, making stacking searches informed by X-ray observations the most promising approach for discovering them within the next decade. Our results demonstrate that joint analyses across multiple neutrino telescopes, together with future MeV gamma-ray observations, will be essential for establishing Seyfert galaxies as astrophysical neutrino sources and provide a means for testing the coronal origin of their neutrino emission.
[abstract 13 / 48] Yes (score: 5) - Title: Spectral Constraints on Line-Seed Inverse-Compton Models for the MeV Feature in GRB 221009AAuthors: Nissim Fraija,Comments: 39 pages, 3 figures, and 7 tables. Submitted to JCAPSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We investigate inverse-Compton (IC) scattering of atomic and molecular line photons as an explanation of the evolving MeV spectral feature observed by FERMI-GBM in GRB 221009A. Detections of H$α$ and Pa$α$ emission from the host galaxy motivate hydrogen recombination seeds, with only indirect support for Ly$α$. A marginal Mg XII feature in the late-time X-ray afterglow provides an event-specific motivation for metal-line seeds, whereas Si XIV, S XVI and iron K-shell transitions are motivated by historical reports of X-ray line features in other GAMMA-RAY BURSTs. Strong late-time H$_2$ emission detected by the James Webb Space Telescope at the projected burst position motivates our most detailed spectral test. Assuming lateral illumination by the H$_2$ $1-0\,S(1)$ transition at $2.122\,μ{\rm m}$, we calibrate lognormal electron distributions to reproduce the observed MeV photon centroids and widths. We also require IC emission from the ultraviolet (UV) photons driving molecular fluorescence to remain compatible with contemporaneous LAT observations. In a separate test including accompanying molecular transitions, the most favourable configuration, based on the Rh3o photodissociation-region model, approximately describes the MeV feature, although all tested configurations exceed the adopted central spectral references at some energies. For an assumed precursor UV budget, favourable interception substantially reduces the seed-photon energy deficit, but even under ideal excitation and internal escape assumptions, the reference-line photon density in the compact examples falls short of the required value by factors of approximately 4-9. Collisional de-excitation, infrared photon escape and electron cooling impose additional constraints on these configurations. Atomic candidates remain kinematically possible, but their local seed-photon supply is also unestablished.
[abstract 14 / 48] Yes (score: 4) - Title: Modeling runaway electron mitigation via passively driven plasma instabilities in a high-current tokamakAuthors: R Datta, C Clauser, G Hu, A Braun, N Ferraro, R Sweeney, R A Tinguely,Comments:Subjects: physics.plasm-phCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
A critical challenge for tokamak-based fusion power plants is the formation of high-current, RELATIVISTIC runaway electron (RE) beams during abrupt confinement loss events called disruptions. RE beams may significantly damage machine components if left unmitigated, jeopardizing the operational and economic viability of fusion power plants. We present the first self-consistent extended MAGNETohydrodynamic (MHD) computational study of RE mitigation with a passively driven RE mitigation coil (REMC) in a high-current tokamak. RE generation and transport are coupled with REMC-driven MHD activity in a 3D simulation that models the thermal and current quench phases of a mid-plane disruption, together with the vertical displacement and final termination of the plasma and RE beam on SPARC -- a high-field, high-current tokamak designed to achieve a fusion gain Q > 1. We demonstrate that REMC-driven MAGNETic stochasticity can reduce the RE current by over an order-of-magnitude when compared to unmitigated disruptions. The final termination is mediated via a post-thermal-quench "cold" vertical displacement of the plasma, which, together with MAGNETic stochasticity, increases RE losses via scrape-off once the plasma contacts the first wall. These results demonstrate a viable mechanism for RE mitigation using passively driven plasma instabilities on high-current tokamaks.
[abstract 15 / 48] Yes (score: 4) - Title: Early--Narrow and Late--Wide Populations of GRB X-ray FlaresAuthors: H. Dereli-Bégué, A. Pe'er,Comments: Submitted to ApJSubjects: astro-ph.HECreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
The physical origin of GAMMA-RAY BURST (GRB) X-ray flares remains debated, particularly whether they arise from prolonged central-engine activity or from variability in the external shock. Building on our previous analysis of 89 SWIFT GRBs with measured redshifts, we investigate the rest-frame temporal properties of X-ray flares detected in 61 bursts. We apply a multivariate Gaussian Mixture Model to rest-frame peak times and widths. We identify two statistically distinct populations: early-narrow flares (80%), with characteristic peak times of approximately 10^2 s and w/t_pk <= 1, and late-wide flares (20%), with characteristic peak times of ~ 10^3.5 s and w/t_pk >= 2. Of the 61 single or first flares, 55 belong to the early-narrow population and only 6 to the late-wide population. Of the 36 second flares, 23 (64%) belong to the early-narrow population, with shorter waiting times, whereas 13 (36%) belong to the late-wide population, with substantially longer waiting times. The width-peak-time correlation remains significant for early-narrow flares but not for late-wide flares. Furthermore, we find no correlation between flare width and energy. We find a decline of flare luminosity with peak time, driven primarily by the early-narrow population, but not statistically significant for late-wide flares. These results imply that a simple shift in time, potentially associated with later episodes of central-engine activity, cannot explain the distinction between the two flare populations. On the other hand, the peak times are consistent with expectations from an accretion disk formed following the collapse of a stellar-size massive star. Combined with our previous finding that flare properties are independent of the presence of an X-ray plateau, these results favor prolonged accretion-driven central-engine activity over external-shock variability as the primary origin of X-ray flares.
[abstract 16 / 48] Yes (score: 4) - Title: A large radiatively loud anti-glitch in 1E 2259+586 with a protracted recoveryAuthors: Han-Long Peng, Ming-Yu Ge, Shan-Shan Weng, Roberto Taverna, Shuang-Nan Zhang, Hua Feng, Yu-Jia Zheng, Kai-Ge Chang, Shi-Jie Zheng,Comments: 8 pages, 5 figures, Accepted in A&ASubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Context. Anti-glitches are rare and enigmatic timing anomalies. High-cadence monitoring has revealed radiatively quiet anti-glitches in several pulsar populations, but radiatively loud anti-glitches and their links to MAGNETospheric activity remain poorly understood. Aims. We characterize a new, large anti-glitch in the MAGNETar 1E 2259+586 and compare its phenomenology with other MAGNETars. Methods. We analyze timing, flux, pulse-profile evolution, and spectra using EP, NICER, and IXPE X-ray observations. Results. We report a 2025 anti-glitch in 1E 2259+586, the largest in this source, with $Δν\approx-1.174(7)\times10^{-7}$ Hz and $Δν/ν\approx-8.19(4)\times10^{-7}$. Unlike its 2019 anti-glitch, this event was radiatively loud: the persistent X-ray flux roughly doubled (~106% increase), followed by a recovery exceeding 320 days. The pulse profile changed modestly but significantly: the valley between the main and secondary peaks became shallower and then recovered with the flux. Spectral properties also changed, and FERMI-GBM detected a short soft GAMMA-RAY BURST near the event. These features resemble the radiatively loud 2012 anti-glitch. Conclusions. 1E 2259+586 is unique among MAGNETars: its anti-glitch rate is comparable to normal spin-up glitch rates, and its anti-glitches can be radiatively loud or relatively quiescent. The fractional anti-glitch amplitudes appear to increase monotonically; further verification is needed. Regular monitoring of 1E 2259+586 is essential for understanding anti-glitch mechanisms.
[abstract 17 / 48] (score: 3) - Title: Science Prospects for the Southern Wide-field Gamma-ray Observatory: SWGOAuthors: SWGO Collaboration, P. Abreu, R. Alfaro, A. Alfonso, M. Andrade, E. O. Angüner, E. A. Anita-Rangel, O. Aquines-Gutiérrez, C. Arcaro, R. Arceo, J. C. Arteaga-Velázquez, P. Assis, H. A. Ayala Solares, A. Bakalova, E. M. Bandeira, P. Bangale, U. Barres de Almeida, P. Batista, I. Batković, J. Bazo, E. Belmont, J. Bennemann, S. Y. BenZvi, A. Bernal, C. Bigongiari, E. Bottacini, R. Branada, P. Brogueira, A. M. Brown, T. Bulik, K. S. Caballero-Mora, P. Camarri, T. Capistrán, M. Cardillo, C. Casentini, C. Castromonte, P. M. Chadwick, J. Chanamé, A. Chiavassa, L. Chytka, R. Colalillo, R. Conceição, G. Consolati, R. R. Cordero, P. J. Costa, R. Covarelli, A. De Angelis, E. de Gouveia Dal Pino, R. de Menezes, P. Desiati, N. Di Lalla, F. Di Pierro, G. Di Sciascio, J. C. Díaz Vélez, C. Dib, B. Dingus, J. Djuvsland, C. Dobrigkeit, L. M. Domingues Mendes, T. Dorigo, M. Doro, A. C. dos Reis, M. Du Vernois, D. Elsaesser, K. Engel, T. Ergin, M. Errando, K. Fang, A. Fazzi, M. Feroci, C. N. Ferreira, N. Fraija, S. Fraija, A. Franceschini, G. F. Franco, S. Funk, R. Galleguillos, A. M. Garcia Reyes, S. Garcia, F. Garfias, G. Giacinti, L. Gibilisco, B. Giovanni, J. Glombitza, H. Goksu, G. Gong, B. S. González, M. M. González, J. Goodman, V. M. Grieco, F. Guarino, G. P. Guedes, J. Gyeong, F. Haist, P. Hansen, J. P. Harding, I. Herzog, J. A. Hinton, W. Hofmann, D. Huang, P. Huentemeyer, A. Iriarte, J. Isaković, A. Jardin-Blicq, L. I. Junoy, J. Juryšek, B. Khelifi, D. Kieda, F. La Monaca, G. La Mura, R. G. Lang, J. S. Lapington, R. Laspiur, L. Lavitola, J. Lee, F. Leitl, M. Lemoine-Goumard, L. Lessio, T. Lewis, B. Liberti, R. A. Lineros, F. Longo, E. Macerata, G. Magugliani, A. Mancilla, D. Mandat, M. Manganaro, M. Mariani, A. Mariazzi, M. Mariotti, T. Marrodán Undagoitia, H. Martínez-Huerta, I. Martins, S. Medina, D. Melo, L. F. Mendes, E. Meza, R. Micali, D. Miceli, S. Miozzi, L. Miramonti, L. S. Miranda, P. E. Mirón Enriquez, A. Mitchell, A. Molinario, A. Montero, O. G. Morales-Olivares, A. Morselli, E. Mossini, M. Mostafá, F. Muleri, F. Nardi, A. P. Nayak, A. Negro, L. Nellen, M. Nisa, V. Novotny, L. Olivera-Nieto, N. Omodei, E. Orlando, S. Ortolani, M. Osorio-Archila, T. Ota, L. Otiniano, A. Paoloni, I. M. Pepe, R. Perca, M. Peresano, Y. Pérez Araujo, T. Petrosillo-Lago, G. Piano, D. Piccolo, A. Pichel, M. Pimenta, M. Pirke, A. Porcelli, T. Porter, E. Prandini, A. Pratts, R. Pretsch, S. Rainò, L. Recabarren, M. Regeard, A. Reisenegger, Q. Remy, H. X. Ren, F. Rescic, B. Reville, M. Reyes, C. D. Rho, M. Riquelme, J. I. Rivadeneira, G. Rodriguez Fernandez, B. Rossi, A. C. Rovero, A. Ruina, E. Ruiz-Velasco, G. Salazar, C. Salotto, F. Sanchez, A. Sandoval, F. Sansone, M. Santander, R. Santonico, G. L. P. Santos, A. Santos-Guevara, D. Sartirana, M. Schneider, M. Schneider, H. Schoorlemmer, F. G. Schröder, F. Schussler, H. Schutte, J. Serna-Franco, M. Shoaib, A. Smith, A. J. Smith, Y. Son, O. Soto, S. T. Spencer, R. W. Springer, J. Stewart, L. A. Stuani, M. Tambone, S. Tapia, M. Tavani, R. Terrier, T. Terzić, K. Tollefson, B. Tomé, I. Torres, E. Torrico Avila, G. C. Trinchero, R. Turner, P. Ulloa, L. Valore, C. van Eldik, J. Vega, I. D. Vergara Quispe, A. Viana, J. Vícha, C. F. Vigorito, V. Vittorini, X. Wang, Z. Wang, M. Waqas, I. J. Watson, F. Werner, R. White, C. Wiebusch, F. Wohlleben, R. Yanyachi, D. Zavrtanik, S. Zhang, P. Zyla,Comments: Accepted for publication in Astroparticle PhysicsSubjects: astro-ph.HE astro-ph.IMCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Ground-based gamma-ray astronomy is now well established as a key observational approach to address critical topics at the frontiers of astroparticle physics and high-energy astrophysics. Whilst the field of TeV astronomy was once dominated by arrays of atmospheric Cherenkov Telescopes, ground-level particle detection has now been demonstrated to be an equally viable and strongly complementary approach. Ground-level particle detection provides continuous monitoring of the overhead sky, critical for the mapping of extended structures and capturing transient phenomena. As demonstrated by HAWC and LHAASO, the technique provides the best available sensitivity above a few tens of TeV, and for the first time access to the PeV energy range. Despite the success of this approach, there is so far no major ground-level particle-based observatory with access to the Southern sky. HESS, located in Namibia, is the only major gamma-ray instrument in the Southern Hemisphere, and has shown the extraordinary richness of the inner galaxy in the TeV band, but is limited in terms of field of view and energy reach. SWGO is an international effort to construct the first wide-field instrument in the south with deep sensitivity from 100s of GeV into the PeV domain. The project is now close to the end of its development phase and planning for construction of the array in Chile has begun. Here we describe the baseline design, expected sensitivity and resolution, and describe in detail the main scientific topics that will be addressed by this new facility and its initial phase SWGO-A. We show that SWGO will have a transformational impact on a wide range of topics from cosmic-ray acceleration and transport to the nature of DARK MATTER. SWGO represents a key piece of infrastructure for multi-messenger astronomy in the next decade, with strong scientific synergies with the nearby CTA Observatory.
[abstract 18 / 48] (score: 3) - Title: Self-organisation through layering of $β$-plane like turbulence in plasmas and geophysical fluidsAuthors: P. L. Guillon, G. Dif-Pradalier, Y. Sarazin, D. W. Hughes, Ö. D. Gürcan,Comments:Subjects: physics.plasm-ph physics.flu-dynCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Staircase formation and layering is studied in simplified, potential vorticity conserving models of plasmas and geophysical fluids, by investigating turbulent self-organisation and nonlinear saturation with different mechanisms of free energy production -- forcing or linear instability -- and with standard or modified zonal flow responses. To this end, staircase formation in both the standard and modified Charney-Hasegawa-Mima equations with stochastic forcing, along with two different simple instability driven models -- one from a plasma and from a geophysical context -- are studied and compared. In these studies, it is observed that $β$-plane turbulence that does not distinguish between zonal and non-zonal perturbations (i.e., standard zonal response) gradually forms large-scale, elliptic zonal structures that merge progressively, regardless of whether it is driven by forcing (though it should be slow enough to allow wave couplings) or by the baroclinic instability, using for example a two-layer model. Conversely, the plasma system, with its modified zonal response, can rapidly form straight, stationary JETs of well-defined size, again regardless of the way it is driven: by stochastic forcing or by the dissipative drift instability. Furthermore, the instability-driven plasma system exhibits a phase transition between a zonal flow dominated state and an eddy dominated state. In both states, saturation is possible without large-scale friction.
[abstract 19 / 48] (score: 3) - Title: Vacuum POLARIZATION and cyclotron resonance effects on radiative transfer and plasma deceleration in subcritical X-ray pulsarsAuthors: I. D. Markozov, A. Y. Potekhin, A. D. Kaminker, A. A. Mushtukov,Comments: 20 pages, 16 figures, 1 table. In v4, Figures 4-14 and Table 1 have been corrected (the Correction is submitted to MNRAS)Subjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We investigate the spectrum and POLARIZATION of radiation emerging from a subcritical X-ray pulsar using self-consistent radiation-hydrodynamic simulations of an accretion channel in a strong MAGNETic field. The polarized radiative transfer in the channel above the hot spot is simulated for the two normal modes, taking into account resonant Compton scattering in a strongly MAGNETized plasma and the effects of vacuum POLARIZATION. We show that the deceleration of the accreting matter in the subcritical regime is mainly governed by resonant scattering. Our simulations provide the velocity profiles of the plasma flow and demonstrate that vacuum POLARIZATION dominates over plasma birefringence, enhancing both the cyclotron spectral feature and the radiative deceleration of the plasma. We also find that the energy of the cyclotron feature increases with accretion luminosity, indicating a positive correlation consistent with previous observational results and theoretical interpretation.
[abstract 20 / 48] (score: 3) - Title: Implementation of a five-wave approximate Riemann solver for general RELATIVISTIC MAGNETohydrodynamics in AthenaKAuthors: Jacob Fields, George N. Wong, James M. Stone,Comments: 19 pages, 15 figures, updated to match accepted versionSubjects: astro-ph.HE gr-qcCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
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 to use the method reliably even when the MAGNETization exceeds $10^4$, which we achieve in a SANE accretion disk. Our SANE disk shows that HLLD leads to a more strongly MAGNETized funnel and more accurate horizon fluxes when compared with HLLE. We further apply the new HLLD implementation to an equal-mass binary neutron star merger. For our long-lived remnant, HLLD enhances the MAGNETic shear stresses in the outer layers and leads to weaker differential rotation. However, due to weaker gravitational wave emissions in the post-merger phase, the remnant is consistently less compact while producing more dynamical ejecta and a more massive disk. The cost of this new solver is relatively modest thanks to the improved initial guess: our accretion disk tests are only ${\sim}10-25\%$ slower than HLLE, and for our binary neutron star runs with a microphysical equation of state, we find that HLLD is only ${\sim}3\%$ slower than HLLE across all runs.
[abstract 21 / 48] (score: 3) - Title: Unidentified Sources in the 4FGL-DR4 FERMI-LAT Catalog as Potential Dark Matter SatellitesAuthors: Fernando Valenciano, Miguel A. Sánchez-Conde, Jorge Martin Camalich,Comments: 14 pages, 10 figures, 4 tables. Comments welcome!Subjects: astro-ph.HE astro-ph.COCreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
The nature of DARK MATTER (DM) remains unknown, standing as one of the most pressing questions in modern physics. We focus on indirect DM detection via gamma-ray emission from annihilating weakly interacting massive particles (WIMPs). Within the $Λ$CDM cosmological framework, the hierarchical assembly of structure predicts a rich population of DM halos and subhalos. If WIMPs compose DM, annihilation inside these subhalos would generate gamma rays that could be detectable by instruments such as the FERMI-LAT. Since 2008, FERMI-LAT has cataloged several thousand of gamma-ray sources, with a third lacking clear astrophysical association. Some of these unassociated sources (unIDs) may actually be dark satellites, i.e., Galactic subhalos not massive enough to retain gas or stars and thus with no counterparts at other wavelengths. Starting from the 14-year FERMI-LAT catalog (4FGL-DR4), we conduct a systematic search for dark satellite candidates among its 2428 unIDs. We first design and apply a series of filters based on expected properties of dark satellites to reduce our sample. Through an exhaustive spectral FERMI-LAT data analysis, we find that none of the remaining unIDs shows a statistically significant preference for a DM interpretation. We place conservative constraints on the $\langleσv\rangle-m_χ$ DM parameter space, which are a factor of 2-3 above the thermal relic cross section value at the lowest WIMP masses in a conservative scenario, and rule out thermally-produced WIMPs below $\sim$50 GeV in the $b\bar{b}$ channel when assuming the sensitivity reach of the method. Our results emphasize the distinctive value of unID-based searches: they yield constraints that complement those derived from classical DM targets, such as dwarf spheroidal galaxies, and probe a unique, cosmologically motivated population of dark satellites otherwise inaccessible to observations.
[abstract 22 / 48] (score: 3) - Title: Accretion variability as a probe of BLACK HOLEs and their environments: Light curve signatures of a single hot spotAuthors: I. Urso, C. Deffayet, A. Held, F. H. Vincent,Comments: Sumbitted to A&ASubjects: astro-ph.HE gr-qcCreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
The compact radio source at the centre of the Milky Way, Sagittarius A*, exhibits temporal broadband brightness variability. The observed timescales of such fluctuations, ranging from minutes to hours on horizon scales, arise from the complex interplay of gravitation, plasma, and light propagation processes in the immediate vicinity of the supermassive BLACK HOLE. Kinetic and fluid simulations associate this variability with turbulence and the formation of MAGNETised, localised plasma structures. Focusing on a single fluctuating compact emission region, a 'hot spot', we study how intrinsic source fluctuations map onto different regions of the observer's screen. Our aim is to identify distinct imprints of light propagation effects, which encode information both about the source and the underlying space-time geometry. We simulate image time series by propagating the emitted light to a distant observer's sky plane in Minkowski, Schwarzschild, and Kerr space-times. We then compute the corresponding observed light curves and power spectra, both for the full observed images and for selected angular sectors of the observer's sky plane. We derive a semi-analytical model for the power spectrum of a fluctuating hot spot in flat space-time, reproducing all qualitative features of curved-space-time spectra at moderate inclinations. Moreover, we describe how such power spectra are affected by space-time geometry, inclination, and source velocity, and show that orthogonal two-sector angular decompositions of the sky plane provide information on system orientation and lensing effects. The physical effects highlighted in this paper are expected to be present in the timing signature of accretion-flow variability, as observed by current instruments and future photometric and interferometric facilities. Further work is needed to investigate if our conclusions hold for realistic disc configurations.
[abstract 23 / 48] (score: 3) - Title: Dust Reverberation Mapping of Low-Mass Active Galactic NucleiAuthors: Chi-Zhuo Wang, Hengxiao Guo, Xue-Bing Wu, Wenwen Zuo, Wanling Liu, Jingbo Sun, Wenke Ren, Shu Wang,Comments: 29 pages, 14 figures, 5 tablesSubjects: astro-ph.GACreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
We perform a systematic dust reverberation mapping study of low-mass ($M_{\mathrm{BH}}\sim10^6$-$10^7 M_\odot$) ACTIVE GALACTIC NUCLEi (AGNs) selected from a literature-compiled catalog, using data from the Zwicky Transient Facility and the Wide-field Infrared Survey Explorer. Through quality assessments, we obtain a core sample of 65 sources with W1- and W2-band lag measurements relative to optical light curves. The W2-band lags are generally longer than the W1-band lags, with a median ratio of $τ_{\mathrm{W2}}/τ_{\mathrm{W1}}=1.24^{+0.33}_{-0.21}$. We further investigate the relations between dust radius and AGN luminosity ($R_{\mathrm{dust}}-L_{\mathrm{AGN}}$), using different lag measurements and luminosity proxies. Combining our sample with a higher-luminosity AGN sample, we establish unified $R_{\mathrm{dust}}-L_{\mathrm{AGN}}$ relations spanning nearly seven orders of magnitude in bolometric luminosity. The slopes are $0.47\pm0.01$ and $0.44\pm0.01$ for the W1 and W2 bands, slightly below the expectation of $0.5$ from dust radiative equilibrium. In the combined sample, the lag deviations show a negative correlation with Eddington ratio, potentially related to the self-shadowing effect of slim disks. The luminosity-dependent SED variations revealed by the SPHEREx composite spectra suggest that individual luminosity proxies may not fully trace the intrinsic dust-heating luminosity. Both effects may contribute to the shallow $R_{\mathrm{dust}}-L_{\mathrm{AGN}}$ slopes. Future joint optical and near-infrared monitoring with the Vera C. Rubin Observatory's Legacy Survey of Space and Time and the Nancy Grace Roman Space Telescope will further extend dust RM studies to lower-luminosity AGNs hosting lower-mass BLACK HOLEs.
[abstract 24 / 48] (score: 3) - Title: AGN feedback destroying group cool cores --- a case study on IC 2476 with a remnant radio AGN and an exceptionally low abundanceAuthors: Wenhao Liu, Ming Sun, Paul Nulsen, Marisa Brienza, Craig Sarazin, Dominique Eckert, Prathamesh Tamhane, Xianzhong Zheng,Comments: 15 pages, 12 figures, ApJ acceptedSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We present results from deep XMM-Newton observations ($\sim$180 ksec) of the galaxy group IC 2476 in the X-GAP sample, capturing a rare AGN feedback regime, where the central radio AGN has ceased activity but the radio lobes are still detectable. The hot intragroup medium of IC 2476 features a compact cool core, with a size of ~10 kpc, and a moderate X-ray luminosity of $\sim3.4\times10^{40}$ erg/s. We measured an unusually low temperature of $\sim$0.45 keV within the cool core. We measured an exceptionally low abundance of below ~0.2 solar, even in the central region. The X-ray surface brightness of the group is not symmetric and shows a clear depression in the region overlaid with the eastern radio lobe, suggesting the presence of an X-ray cavity. The scaled entropy of the hot gas within 0.1 r500 of IC 2476 is among the highest in X-ray galaxy groups with a similar system temperature. Our study suggests that the past powerful radio AGN outburst in IC 2476 has disrupted the cool core and the X-ray cavity has dissipated or mixed with the surrounding hot gas since the shutdown of the central AGN. A large cool core may be gradually re-established in the absence of AGN activity. This system therefore provides a great example of AGN feedback destroying the group cool core, even with a moderate radio luminosity at present.
[abstract 25 / 48] (score: 3) - Title: Ultra-high-energy COSMIC RAYs require metal-rich sourcesAuthors: E. Podlesnyi, F. Oikonomou, D. Ehlert, M. Unger,Comments: 10 pages, 6 figures, Supplemental MaterialSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
The elemental composition of ultra-high-energy COSMIC RAYs (UHECRs) must be evaluated at a given rigidity rather than energy to compare with candidate elemental abundances, such as those of low-energy COSMIC RAYs seeding the acceleration of UHECRs. We determine the UHECR composition from fits to Pierre Auger Observatory data and evaluate the resulting abundances at fixed rigidity. We identify two classes of solutions consistent with measurements above $10^{17.8}$ eV: one in which the hydrogen flux at Earth is dominated by secondary nucleons produced by photodisintegration of heavier nuclei in extragalactic photon fields, and a second in which this contribution is less pronounced. Only the latter, which yields a mixture of primary and secondary protons at Earth, allows a hydrogen abundance at the source comparable to that of low-energy COSMIC RAYs. However, both classes of solutions require an overabundance of nuclei in the silicon-iron group. Other source models from the literature also fail to reproduce the full elemental composition. The metallicity of UHECRs thus differs markedly from that of all candidate seed populations considered, leaving the origin of the heavy-element excess unresolved.
[abstract 26 / 48] (score: 3) - Title: Two-component $γ$-Ray Structure from the CR SourcesAuthors: Lin Nie, Ming-Jun Chen, Zong-Kang Zeng, Yi-Qing Guo,Comments: 18 pages, 4 figuresSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
With the advent of a new generation of observational experiments and the accumulation of data, an increasing number of cosmic-ray sources have been found to exhibit pronounced two-component structures in their gamma-ray spectra above GeV energies. To investigate whether these structures share a common physical origin, we conduct a statistical study of sources exhibiting such features using a two-component model of cosmic-ray sources and examine their gamma-ray emission mechanisms. We find that the ambient environment significantly affects the spectral morphology. Sources located in low-density environments but surrounded by dense molecular clumps exhibit two clearly separated spectral peaks. In contrast, sources embedded in dense environments with additional dense molecular clumps nearby retain two-component spectral features, but the components overlap more smoothly, with the high-energy component appearing primarily as a relatively broad shoulder rather than a distinct peak. Our results lend further support to a physical picture in which high-energy COSMIC RAYs are predominantly supplied by local sources, whereas low-energy COSMIC RAYs arise mainly from the collective contribution of sources in other regions of the Galaxy. We also calculate the neutrino spectra of these sources, providing theoretical predictions for future tests of the model through observations of point-source and diffuse neutrino emission.
[abstract 27 / 48] (score: 3) - Title: Probing for anisotropies at different angular scales in the arrival directions of the COSMIC RAYs detected at the Pierre Auger ObservatoryAuthors: The Pierre Auger Collaboration, A. Abdul Halim, P. Abreu, M. Aglietta, M. Ahmed, I. Allekotte, K. Almeida Cheminant, R. Aloisio, J. Alvarez-Muñiz, A. Ambrosone, J. Ammerman Yebra, L. Anchordoqui, B. Andrada, L. Andrade Dourado, L. Apollonio, C. Aramo, J. C. Arteaga Velázquez, P. Assis, G. Avila, E. Avocone, A. Bakalova, Y. Balibrea, A. Baluta, F. Barbato, A. Bartz Mocellin, O. Batalla Cruz, J. P. Behler, C. Berat, M. E. Bertaina, M. Bianciotto, P. L. Biermann, V. Binet, K. Bismark, T. Bister, J. Biteau, J. Blazek, J. Blümer, M. Boháčová, D. Boncioli, C. Bonifazi, P. Boril, N. Borodai, J. Brack, P. G. Brichetto Orquera, S. Buitink, A. Bwembya, T. R. Caba Pineda, K. S. Caballero-Mora, S. Cabana-Freire, L. Caccianiga, J. Caraça-Valente, R. Caruso, A. Castellina, F. Catalani, G. Cataldi, L. Cazon, M. Cerda, B. Čermáková, A. Cermenati, K. Cerny, J. A. Chinellato, J. Chudoba, L. Chytka, R. W. Clay, A. C. Cobos Cerutti, R. Colalillo, R. Conceição, G. Consolati, M. Conte, F. Convenga, D. Correia dos Santos, P. J. Costa, C. E. Covault, M. Cristinziani, C. S. Cruz Sanchez, S. Dasso, K. Daumiller, B. R. Dawson, R. M. de Almeida, E. -T. de Boone, B. de Errico, J. de Jesús, S. J. de Jong, J. R. T. de Mello Neto, I. De Mitri, D. de Oliveira Franco, F. de Palma, V. de Souza, E. De Vito, A. Del Popolo, O. Deligny, N. Denner, K. Denner Syrokvas, L. Deval, A. di Matteo, C. Dobrigkeit, J. C. D'Olivo, L. M. Domingues Mendes, T. Dominguez, Y. Dominguez Ballesteros, Q. Dorosti, R. C. dos Anjos, J. Ebr, F. Ellwanger, R. Engel, M. Erdmann, A. Etchegoyen, C. Evoli, H. Falcke, G. Farrar, A. C. Fauth, T. Fehler, F. Feldbusch, A. Fernandes, M. Fernández Alonso, B. Fick, J. M. Figueira, P. Filip, A. Filipčič, B. Flaggs, A. Franco, M. Freitas, T. Fujii, A. Fuster, C. Galea, C. Galelli, B. García, C. Gaudu, P. L. Ghia, U. Giaccari, M. Giammarco, C. Glaser, F. Gobbi, F. Gollan, G. Golup, P. F. Gómez Vitale, J. P. Gongora, N. González, D. Góra, A. Gorgi, M. Gottowik, F. Guarino, G. P. Guedes, Y. C. Guerra, S. Hahn, P. Hamal, M. R. Hampel, P. Hansen, D. Harari, V. M. Harvey, A. Haungs, M. Havelka, T. Hebbeker, C. Hojvat, J. R. Hörandel, P. Horvath, M. Hrabovský, T. Huege, A. Insolia, P. G. Isar, M. Ismaiel, P. Janecek, V. Jilek, K. -H. Kampert, L. Karczubová, B. Keilhauer, V. V. Kizakke Covilakam, H. O. Klages, M. Kleifges, A. Klingel, J. Köhler, F. Krieger, M. Kubatova, B. L. Lago, N. Leal, M. A. Leigui de Oliveira, Y. Lema-Capeans, A. Letessier-Selvon, I. Lhenry-Yvon, L. Lopes, P. Magnani, M. Mallamaci, S. Mancuso, D. Mandat, P. Mantsch, A. G. Mariazzi, C. Marinelli, I. C. Mariş, G. Marsella, D. Martello, S. Martinelli, O. Martínez Bravo, A. Martínez-Mendez, M. A. Martins, H. -J. Mathes, J. Matthews, G. Matthiae, E. Mayotte, S. Mayotte, P. O. Mazur, G. Medina-Tanco, D. Melo, A. Menshikov, C. Merx, S. Michal, M. I. Micheletti, L. Miramonti, M. Mogarkar, S. Mollerach, F. Montanet, L. Morejon, K. Mulrey, R. Mussa, W. M. Namasaka, S. Negi, L. Nellen, G. A. Neves, K. Nguyen, G. Nicora, M. Niechciol, D. Nitz, D. Nosek, A. Novikov, V. Novotny, L. Nožka, A. Nucita, L. A. Núñez, S. E. Nuza, J. Ochoa, M. Olegario, C. Oliveira, L. Östman, M. Palatka, J. Pallotta, G. Parente, T. Paulsen, M. Pech, J. Pękala, R. Pelayo, D. Perez, C. Pérez Bertolli, L. Perrone, S. Petrera, T. Pierog, M. Pimenta, M. Platino, P. Privitera, C. Priyadarshi, M. Prouza, K. Pytel, S. Querchfeld, L. Ramella, J. Rautenberg, D. Ravignani, J. V. Reginatto Akim, A. Reuzki, J. Ridky, F. Riehn, M. Risse, V. Rizi, B. Rocha-Moldes, E. Rodriguez, G. Rodriguez Fernandez, J. Rodriguez Rojo, M. Roth, E. Roulet, A. C. Rovero, A. Saftoiu, M. Saharan, F. Salamida, H. Salazar, G. Salina, P. Sampathkumar, N. San Martin, J. D. Sanabria Gomez, F. Sánchez, F. M. Sánchez Rodriguez, E. Santos, F. Sarazin, R. Sarmento, R. Sato, P. Savina, V. Scherini, H. Schieler, M. Schimp, D. Schmidt, O. Scholten, H. Schoorlemmer, P. Schovánek, F. G. Schröder, J. Schulte, T. Schulz, S. J. Sciutto, M. Scornavacche, A. Sedoski, S. Sehgal, S. U. Shivashankara, G. Sigl, K. Simkova, F. Simon, R. Šmída, S. Soares Sippert, P. Sommers, S. Stanič, J. Stasielak, P. Stassi, S. Strähnz, M. Straub, T. Suomijärvi, A. D. Supanitsky, Z. Svozilikova, Z. Szadkowski, F. Tairli, A. Tapia, C. Taricco, C. Timmermans, O. Tkachenko, P. Tobiska, C. J. Todero Peixoto, B. Tomé, A. Travaini, P. Travnicek, C. Trimarelli, M. Tueros, M. Unger, R. Uzeiroska-Geyik, L. Vaclavek, M. Vacula, I. Vaiman, J. F. Valdés Galicia, L. Valore, P. van Dillen, E. Varela, V. Vašíčková, D. Veberič, M. A. Vega Caro, I. D. Vergara Quispe, S. Verpoest, V. Verzi, J. Vicha, L. M. A. Victoria, S. Vorobiov, J. B. Vuta, A. A. Watson, A. Weindl, M. Weitz, L. Wiencke, H. Wilczyński, B. Wundheiler, B. Yue, A. Yushkov, E. Zas, D. Zavrtanik, M. Zavrtanik, M. Zeferino Rennó,Comments: 19 pages, 7 figuresSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Studies of the arrival-direction distribution of ultra-high-energy COSMIC RAYs are crucial for revealing their origin. In this work, we investigate the distribution of the arrival directions of events detected with the Pierre Auger Observatory over different angular scales. To do this, we adopt a novel method where we use a von Mises--Fisher distribution to model the excesses with respect to isotropic expectations. This method allows us to study the distribution of arrival directions over different angular scales consistently and simultaneously. We consider the events in different energy bins above 4 EeV detected from 1$^\text{st}$ January 2004 to 31$^\text{st}$ December 2022, i.e. during the entire Phase~I of the Pierre Auger Observatory, with a total exposure of $123{,}000$ km$^2$ sr yr. The most significant excess in the bins considered is a dipolar modulation in the energy range (8--16) EeV, which is compatible with previous findings of the Pierre Auger Collaboration. A dipolar modulation appears to be present for the higher energies considered as well, and at the highest energies, i.e. above 32 EeV, we find indications of its coexistence with an overdensity of intermediate angular scale, located in the Centaurus region.
[abstract 28 / 48] (score: 3) - Title: Leveraging Lensing-driven Early Warnings: Joint Detectability of lensed Gravitational Waves and their LSST Optical CounterpartsAuthors: Sourabh Magare, Anindya, Anupreeta More, Shasvath J. Kapadia,Comments: 19 pages, 9 figuresSubjects: astro-ph.HE astro-ph.COCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Gravitational lensing of gravitational waves (GWs) can be leveraged to provide early-warning times of $\mathcal{O}(\mathrm{hours})$ to $\mathcal{O}(\mathrm{days})$ prior to the mergers of binary neutron stars (BNSs) and neutron star-BLACK HOLEs (NSBHs). This capability could, in turn, enable electroMAGNETic (EM) observatories to capture transient emissions surrounding the time of the merger. In this work, we demonstrate the viability of jointly detecting gravitationally lensed BNS and NSBH mergers via GWs during the O5 observing run, alongside their associated kilonova counterparts using the Legacy Survey of Space and Time (LSST). We simulate a population of lensed BNS and NSBH mergers detectable during O5 and utilize current benchmark forward models to generate the corresponding lensed kilonova light curves. We then assess the detectability of these light curves across LSST bands under various exposure limits. We find that among the detectable lensed mergers in O5, approximately 60\% of the BNS kilonova and 10\% of the NSBH kilonova will be observable within a single LSST exposure, with mostly quads dominating the detectable population. Furthermore, we define a detectability index ($\rm DI$), which determines the EM-detectability in optical of lensed GW-detectable BNS and NSBH mergers. We demonstrate the robustness and generalizability of the $\rm DI$ on our lensed BNS and NSBH population. Our work demonstrates that lensing-driven early warnings will be highly applicable in the near future, enabling the LSST to effectively follow up on BNS and NSBH triggers within GW localization areas during the O5 observing run.
[abstract 29 / 48] (score: 2) - Title: Investigating production of TeV-scale muons in extensive air shower at 2400 m undergroundAuthors: Xinshun Zhang, Shaomin Chen, Wei Dou, Haoyang Fu, Guanghua Gong, Lei Guo, Ziyi Guo, XiangPan Ji, Jianmin Li, Jinjing Li, Bo Liang, Ye Liang, Qian Liu, Wentai Luo, Ming Qi, Wenhui Shao, Haozhe Sun, Jian Tang, Yuyi Wang, Zhe Wang, Changxu Wei, Jun Weng, Yiyang Wu, Benda Xu, Chuang Xu, Tong Xu, Tao Xue, Haoyan Yang, Yuzi Yang, Aiqiang Zhang, Bin Zhang, Yang Zhang, Zhicai Zhang, Lin Zhao, Yangheng Zheng,Comments: 10 pages, 5 figures, 2 tables; final author version incorporating EPJC revisions and proof correctionsSubjects: hep-ex astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Deep underground experiments present a new avenue to probe the first interactions in extensive air showers or hadronic interactions in the extreme forward phase space. The China Jinping Underground Laboratory, characterized by a vertical rock overburden of 2,400 m, provides an exceptionally effective shield against cosmic muons with energies below 3 TeV. The surviving high-energy muons, produced in the first interactions of extensive air showers, open a unique observational window into primary COSMIC RAYs from tens of TeV up to the PeV scale and beyond. This distinctive feature also enables detailed studies of charged hadron production in the earliest stages of shower development. Using 1,338.6 live days of data collected with a one-ton prototype detector for the Jinping Neutrino Experiment, we measured the underground muon flux originating from air showers. The results show discrepancies of about 40% corresponding to significances of more than 2$σ$, relative to predictions from several leading hadronic interaction models. We interpret these findings from two complementary perspectives: (i) by adopting the expected cosmic-ray spectra, we constrain the modeling of the first hadronic interactions in air showers and provide novel insights into resolving the long-standing muon puzzle; and (ii) by assuming specific hadronic interaction models, we infer the mass composition of COSMIC RAYs, and our data favor a lighter component in the corresponding energy range. Our study demonstrates the potential of deep underground laboratories to provide new experimental insights into air shower physics and COSMIC RAYs.
[abstract 30 / 48] (score: 2) - Title: micrOMEGAs 7: Beyond standard cosmologyAuthors: G. Belanger, A. Belyaev, N. Bernal, F. Boudjema, S. Chakraborti, A. Goudelis, A. Pukhov,Comments: 32 pages, 6 figures. Program summary added, flowchart addedSubjects: hep-phCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We present micrOMEGAs7, a major upgrade of the micrOMEGAs package for the computation of DARK MATTER observables in generic models. This release introduces a generalized treatment of the Boltzmann equations, allowing for user-defined modifications of the Hubble expansion rate, entropy evolution, and non-thermal DARK MATTER production from late-decaying cosmological components, thereby extending the framework beyond the standard radiation-dominated cosmology. The relic density can now be computed in scenarios such as low-temperature reheating, early matter domination, and kination. The new version also improves the treatment of sub-GeV DARK MATTER, in particular annihilation into light mesons through scalar mediators, and provides updated spectra for indirect detection. Several experimental and observational constraints have been implemented or revised, including CMB bounds from Planck on energy injection during recombination and FERMI-LAT limits from dwarf spheroidal galaxies. For direct detection, a recast of recent LZ results has been included, and the code now takes into account effective electroMAGNETic couplings of spin-$1/2$ and spin-1 DARK MATTER. Collider observables have also been extended through the implementation of CMS dilepton resonance constraints on $Z'$ mediators. Additional improvements include a more flexible treatment of effective RELATIVISTIC degrees of freedom and an updated LHAPDF interface.
[abstract 31 / 48] (score: 2) - Title: Heavy-element dust as an explanation for the late-time kilonova spectraAuthors: Nanae Domoto, Kenta Hotokezaka, Daniel Kasen,Comments: 20 pages, 10 figures, accepted for publication in ApJSubjects: astro-ph.HE astro-ph.SRCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Neutron star mergers are a leading site of r-process, producing radioactively powered optical and infrared transients known as kilonovae. Observations of the kilonovae AT2017gfo, associated with the gravitational-wave event GW170817, and AT2023vfi, associated with GRB 230307A, have enabled measurements of the mass of ejected r-process material and identification of heavy elements in the ejecta. However, late-time observations reveal strong infrared emission with temperature below 1000 K, which is difficult to explain by atomic absorption and emission processes alone. In this paper, we propose that kilonova ejecta provide conditions favorable for the formation of dust grains composed of refractory r-process elements including Zr, W, and Os. Assuming a simplified, empirically derived single power-law temperature evolution and using W reaction rate coefficients as a proxy, our kinetic dust formation calculations indicate that dust could form efficiently, particularly in slow ejecta. This stands in contrast to a previous study that relied on a classical nucleation framework. By performing radiative transfer simulations that incorporate dust formation, we demonstrate that, if formed, r-process dust could naturally explain the observed late-time infrared emission, although refining ejecta parameters and geometry will be necessary to match specific observational cases. The formation and abundance of r-process dust are highly sensitive to ejecta mass, composition, and expansion velocity. Infrared emission from r-process dust may therefore potentially serve a new probe of heavy-element production in neutron star mergers.
[abstract 32 / 48] (score: 2) - Title: ACORN I. Massive Black Hole Seeding and Tidal Disruption Events from Star Clusters in Cosmological SimulationsAuthors: Yihao Zhou, Tiziana Di Matteo, Claire E. Williams, Aklant Kumar Bhowmick, Marta Reina-Campos, Carl L. Rodriguez, Elena González Prieto, Laura Blecha, Rupert Croft,Comments: 34 pages, 26 figures. Submitted to ApJ. Comments are welcome!Subjects: astro-ph.GA astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
JWST has revealed massive star clusters at $z\gtrsim 6$, which provide promising environments for massive BLACK HOLE (MBH) seed formation. We introduce a new MBH seeding model for cosmological simulations, physically motivated by runaway collisions in star clusters. Subgrid star clusters are generated according to the local ISM and evolved through stellar evolution and two-body relaxation. The masses of MBH seeds formed through runaway collisions are determined by the properties of their host clusters, including the effects of metallicity-dependent stellar winds. We further follow tidal disruption events (TDEs) with the evolving clusters, which can be enhanced in MBH binaries, and account for gravitational-wave (GW) recoil following MBH mergers. We implement this model in a constrained simulation of a 5$σ$ overdense region, where seeds of $10^{3}-10^{5.6}\,M_\odot$ form in clusters with $10^{4}\leq m_{\rm SC}\leq 10^{8}\,M_\odot$. Because both the seed abundance and mass are directly connected to the local environment, we have a more physical $M_{\rm BH}\!-\!M_{\rm galaxy}$ scaling for low-mass galaxies ($M_{\rm galaxy}\sim10^{6-9}\,M_\odot$), a regime poorly described by previous seeding models. Multiple MBHs are naturally allowed to form in-situ within individual halos, producing a spatially clustered population. This increases the MBH merger rate by $\sim100$ relative to other seeding models, significantly enhancing the expected LISA event rate. TDEs can dominate the growth of $10^{3-4}\,M_\odot$ MBHs and produce luminous flares of $L_{\rm peak}\sim 10^{42-43}\,{\rm erg\,s^{-1}}$, increasing the observability of low-mass seeds. This seeding prescription accelerates early MBH growth at $z\gtrsim 8$, while subsequent self-regulated gas accretion drives the central MBH toward similar masses $\sim10^{9}\, M_\odot$ by $z=6$ across different seeding models.
[abstract 33 / 48] (score: 2) - Title: A componentwise spherical Dirichlet-to-Neumann closure for finite-volume MHD at finite MAGNETic Reynolds numberAuthors: Min Ki Jung, Brian Wynne, Francisco Saenz, Yufan Xu, Egemen Kolemen, Yong-Su Na,Comments:Subjects: physics.comp-ph physics.flu-dynCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
At finite MAGNETic Reynolds number, the field induced by a moving conducting fluid or solid extends into open space, so a finite mesh needs an outer boundary condition that represents the decaying exterior field. Magnetohydrodynamic (MHD) codes widely use pseudo-vacuum or truncation at a finite radius. Neither condition is physically correct for a vacuum exterior, but the exact alternatives are costly or limited to simple geometries. We present a Dirichlet-to-Neumann (DtN) closure on a fixed enclosing sphere and release it as part of the open-source multi-region finite-volume solver FreeMHD. The closure matches each Cartesian component of the vector potential to its decaying exterior solution, which retains all three decaying vector-Laplace families. A meshed vacuum buffer connects non-spherical conductors to the sphere. We verify the closure with manufactured modes, sphere free decay, sphere and oblate dynamos, and a freely braking rotor. Under refinement, oblate dynamo thresholds and sphere growth rates converge toward independent spectral references, and the rotor torque matches an exact transient reference. On the same sphere, pseudo-vacuum and truncation give the larger errors predicted by their exterior models. The DtN closure achieves the accuracy of a distant outer boundary with a compact domain.
[abstract 34 / 48] (score: 2) - Title: Short-term optical monitoring of quadruply imaged QUASARsAuthors: L. J. Goicoechea, V. N. Shalyapin, A. Esteban-Gutiérrez, R. Gil-Merino, M. Serra-Ricart,Comments: 13 pages, 13 figures, 10 tables. Accepted for publication in Astronomy and AstrophysicsSubjects: astro-ph.COCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We present two case studies to demonstrate that short-term optical monitoring campaigns of quadruply imaged QUASARs (quads) reveal their astrophysical potential. Using the Liverpool Telescope and the third facility of the Two-meter Twin Telescope (TTT3), we monitored the quads QSO 2237+0305 and PS J0147+4630 in the gr bands between July 2025 and January 2026. For QSO 2237+0305, the resulting light curves revealed microlensing variability over a timescale of ~150 days. The g-band difference light curve between images A and B was then used to reliably constrain the half-light radius of the g-band source within the 3.5-16 lt-day range (1σ confidence level). For PS J0147+4630, we derived new constraints on the AB and AC time delays from the r-band light curves of the ABC images in an arc-like configuration, obtaining 2σ uncertainties of ~2 days. These constraints were used to shed light on the lensing mass distribution. Overall, our results validate the design of short-term optical monitoring campaigns of quads as valuable astrophysical tools in the era of large-scale surveys. The proof of concept relies on observations with ground-based 2mclass telescopes that lack sophisticated systems to correct for optical distortions caused by atmospheric turbulence, and we indicate the astro-photometric properties of the targets and the monitoring strategies needed to achieve success with these telescopes. Additionally, this work represents the first validation of the TTT3 facility for precision photometric monitoring of gravitationally lensed QUASARs.
[abstract 35 / 48] (score: 2) - Title: Standalone Validation of a Pulsar Evolution Subroutine for NBODY6++GPU: Seven Test ScenariosAuthors: Maria Rah,Comments: Accepted for publication in Research in Astronomy and Astrophysics (RAA). 22 pages, 15 figuresSubjects: astro-ph.HECreated: 2026-11-07; Updated: 2026-11-11; Datestamp: 2026-11-11
Pulsars in globular clusters provide critical constraints on the evolution of compact objects. However, the treatment of neutron stars in standard N-body codes is outdated, and requires a better implementation of MAGNETic field decay, spin evolution, and accretion driven recycling that shape their observable properties. We present a standalone validation of a pulsar evolution subroutine for NBODY6++GPU, systematically tested across seven controlled scenarios prior to integration into full cluster simulations. These scenarios isolate distinct evolutionary regimes, including young pulsar spin down, millisecond pulsar weak torque evolution, accretion driven recycling in X-ray binaries, environmental torques in dense cores, wide binary systems, and compact binaries in the dipole spin-down regime. Through two separate numerical implementations, we achieve cross validation demonstrating better than 0.1% agreement across all physical quantities and timescales. Our validation confirms that analytical solutions are reproduced with high precision for isolated pulsars, gigayear scale evolution (tau_c ~ 1.0 Gyr) matches observations of millisecond pulsars in clusters like 47 Tucanae, and accretion driven recycling operates with physically realistic timescales, yielding a final period of 1.0 ms and a period derivative of approximately -5.9e-19 s/s, with accretion dominance by a factor of about 14. We demonstrate that environmental torques remain negligible even in the densest cluster environments, while compact binary spin down is validated; gravitational wave orbital decay is deferred to future work. All validation codes, test suites, and integration instructions are publicly available to support future applications.
[abstract 36 / 48] (score: 2) - Title: The Impact of a Magnetic Field on stochastically generated g-modesAuthors: T. M. Rogers, L. M. Corrigan, L. Barrault, R. P. Ratnasingam,Comments: 24 pages, 20 figures. Accepted at ApJSubjects: astro-ph.SRCreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
Magnetic fields have been proposed as a mechanism for suppressing low-frequency gravity modes in stellar interiors, providing a means of constraining internal MAGNETic field strengths. However, previous suppression criteria have largely relied on linear theory. Here, we use two-dimensional nonlinear MAGNETohydrodynamic (MHD) simulations in a core convecting star to investigate the interaction of gravity waves with MAGNETic fields of varying strengths and geometries. Using both global and local field geometries, we find that amplitude reduction is gradual and frequency dependent, with low-frequency modes preferentially attenuated while higher-frequency modes can be amplified. In order to achieve significant suppression we require a MAGNETic field strength at least an order of magnitude larger than predicted by commonly used linear criteria. Its likely that this difference arises because MAGNETic fields can themselves excite waves through Maxwell stresses, offsetting MAGNETic attenuation. Our results demonstrate that strong MAGNETic modifications to wave propagation do not necessarily result in equivalent suppression of the global oscillation spectrum. The linear criteria typically used to infer field strengths based on mode suppression does not capture all relevant physics and should be used with care.
[abstract 37 / 48] (score: 2) - Title: Revealing Hidden Excitation in the Core of NGC 4696: New Infrared Diagnostic Diagrams with JWSTAuthors: Olivia R Pereira, Julie Hlavacek-Larrondo, Michael Reefe, Gary J Ferland, Hyunseop Choi, Mathieu Marquis, Jorge Barrera-Ballesteros, Benjamin Vigneron, Ming Sun, Rebecca E A Canning, Gregory Taylor, Loic Albert, Francesco D'Eugenio, Megan Donahue, Andrew C Fabian, John S Gallagher, Marie-Lou Gendron-Marsolais, Pierre Guillard, Minghao Guo, Nina Hatch, Ralf Kotulla, Yuan Li, Roberto Maiolino, Allison Man, Michael A McDonald, Brian R McNamara, Valeria Olivares, Marine Prunier, Christopher S Reynolds, Carter Rhea, Annabelle Richard-Laferriere, Helen R Russell, Philippe Salome, Prathamesh Tamhane, Auriane Thilloy, Grant R Tremblay, G Mark Voit, Stephen A Walker,Comments: Submitted to ApJ and revised in response to referee comments (32 pages, 10 figures)Subjects: astro-ph.GA astro-ph.HECreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
The warm molecular and ionized gas in filamentary nebulae of cool-core BCGs provide a sensitive probe of the poorly understood exchange of energy between the ICM, cold molecular gas, and AGN feedback. Optical line ratios commonly yield similar LINER-like classifications across these systems, but do not resolve how the excitation of warm molecular gas varies between compact nuclear structures and surrounding filaments. We present JWST/NIRSpec integral-field spectroscopy of the central $3''\times3''$ ($620\times620~{\rm pc^2}$) of the Centaurus cluster BCG, NGC~4696. The NIR data resolve H$I$ and ro-vibrational H$_2$ emission across compact nuclear apertures, a circumnuclear swirl, and filamentary structures. H$_2$ excitation diagrams yield characteristic low-excitation temperatures of $T_{\rm ex}\simeq1.8-2.2\times10^3$~K, while curvature at higher energies requires hotter or non-thermal components. The H$_2$/Pa$α$ balance varies strongly: filamentary regions have H$_2$ 1-0 S(1)/Pa$α$ ratios 4-8 times higher than the compact nuclear apertures. In contrast, matched-aperture optical diagnostic diagrams show substantially less regional separation, with all regions occupying a low-ionization locus. We thus introduce new spatially resolved NIR diagnostic diagrams that reveal distinct molecular excitation conditions across the nucleus, swirl, and filaments. Ratios are broadly consistent with contributions from AGN-related photoionization, ICM-related cooling radiation, and non-radiative heating, although the present data do not uniquely determine their relative importance. These results demonstrate how spatially resolved NIR spectroscopy reveals excitation variations hidden in conventional optical classifications, providing a new route to constrain the multiphase cooling-feedback cycle in cluster cores.
[abstract 38 / 48] (score: 2) - Title: High-power X-Point Target divertor experiments on the TCV tokamakAuthors: K. Lee, M. Carpita, C. Theiler, M. Zurita, O. Février, A. Mele, R. I. Morgan, F. Pastore, H. Reimerdes, K. Verhaegh, M. Winkel, D. Brida, B. Y. K. Brown, M. J. H. Cornelissen, R. Ducker, G. Durr-Legoupil-Nicoud, D. Hamm, M. Pedrini, A. Perek, O. Sauter, P. Sintre, E. Tonello, Y. Wang, the TCV Team, the EUROfusion Tokamak Exploitation Team,Comments: 18 pages, 12 figuresSubjects: physics.plasm-phCreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
Stationary power exhaust in the X-Point Target (XPT) divertor configuration is investigated in high-power ($2.5\,\text{MW}$) TCV L-mode discharges, in which the Lengyel detachment scaling metric $P_{\text{SOL}}B_{0}/(R_{0}n_{e,\text{u}}^{2})$ lies in the range expected for reactors (SPARC, ITER, ARC). Compared with a conventional single-null (SN) divertor, the XPT improves power exhaust performance, reducing the peak outer target heat flux by 40--60\% and enabling divertor detachment with nitrogen seeding under conditions in which the SN cannot be detached. Detachment evolves asymmetrically across the multiple XPT outer strike points. The sensitivities of the peak target heat fluxes and impurity emission front positions to the X-point separation ($\text{d}R_{\text{u},X2}$) are characterized and found to decrease at higher nitrogen seeding levels. Field-reversal experiments reveal the critical role of $E\times B$ drifts inherent to the MAGNETic topology of the secondary X-point, which drive an unconventional redistribution of density and impurity radiation in the XPT divertor and thereby cause the asymmetries between the XPT outer strike points, largely confirming the expectations from recent SOLPS-ITER modelling. A framework for understanding the power exhaust physics of the XPT is presented, detailing the roles of SOL splitting, connection length peaking, $E\times B$ drifts, and vessel geometry. Together, these results establish an experimental physics basis for the XPT divertor as a potential power exhaust solution for tokamak reactors.
[abstract 39 / 48] (score: 2) - Title: Polarized Equatorial Emission around Kerr Black Holes with Synchronized Scalar Hair. II. Indirect imagesAuthors: Valentin O. Deliyski, Tsanimir Angelov, Galin N. Gyulchev, Stoytcho S. Yazadjiev,Comments:Subjects: gr-qcCreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
We investigate the intensity POLARIZATION properties of the indirect images of a geometrically and optically thin accretion disk around fully self-consistent models of Kerr BLACK HOLEs with synchronized scalar hair. The presence of a massive, self-gravitating scalar field can dramatically alter the lensing properties of the spacetime, resulting in morphologically complex indirect images. We show that for a representative high scalar charge model, this results in the presence of high order central ring-like images at low observer inclinations. These images are not exponentially demagnified, and their polarized intensity, relative to the direct images, is significant. We therefore conclude that the observational signature of strongly scalarized Kerr BLACK HOLEs may not be dominated solely by the $n=1$ image, as images with $n\geq2$ may also contribute significantly to the observed polarized emission, depending on the radial emissivity profile of the disk and the observer inclination.
[abstract 40 / 48] (score: 2) - Title: Identification of the C IV $λλ$5801, 5812 Emission in the Off-Nuclear TDE 2025abcrAuthors: Jingbo Sun, Hengxiao Guo, Sjoert van Velzen, Yuhan Yao, Mar Mezcua, Stefan Geier, Alok C. Gupta, Karan Dogra, Philip G. Edwards, Wenwen Zuo, Yu Pan, Minfeng Gu,Comments:Subjects: astro-ph.HE astro-ph.GACreated: 2026-11-09; Updated: 2026-11-11; Datestamp: 2026-11-11
TDE 2025abcr is a tidal disruption event (TDE) located approximately 9 kpc in projection from its host galaxy nucleus. Our spectroscopic follow-up with the Very Large Telescope (VLT) reveals C IV $λ\lambda5801, 5812$ emission, representing the first identification of this C IV doublet in a TDE. These transitions are uncommon in ACTIVE GALACTIC NUCLEi (AGN) spectra but have been observed in SUPERNOVA flash spectra and Wolf-Rayet (WR) stars. We propose that the doublet arises from the combined effects of continuum fluorescence and photon trapping in the 312 Å transition, analogous to the mechanism operating in nitrogen-sequence Wolf-Rayet (WN) winds. This mechanism requires intense extreme-ultraviolet (EUV) illumination and a high optical depth, providing a distinctive diagnostic of the physical conditions in optically thick TDE outflows. These requirements, together with the relatively narrow widths of the broad emission lines, the presence of Bowen fluorescence features, and the small inferred blackbody radius, favor a compact and dense envelope in TDE 2025abcr. The optical C IV doublet may have been overlooked in previous observational and theoretical studies of TDEs, motivating more detailed radiative-transfer calculations for optically thick outflows. With future TDE samples from Rubin/LSST and WFST, a larger C IV TDE sample will test if this population systematically favors a compact photosphere.
[abstract 41 / 48] (score: 2) - Title: Compact plasma-based extreme compression of RELATIVISTIC electron beamsAuthors: Rafi Hessami, Kelly K Swanson, Mario Galletti, Livio Verra, Angelo Biagioni, Lucio Crincoli, Mariano Carpanese, Martina Del Giorno, Francesco Demurtas, Giacomo Griseri, Valerio Lollo, Michele Opromolla, Federico Nguyen, Gianmarco Parise, Alberto Petralia, Gilles J Silvi, Federica Stocchi, Marco Zottola, Agostino Marinelli, Riccardo Pompili, Claudio Emma,Comments:Subjects: physics.acc-ph physics.plasm-phCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Accelerated particle beams are essential tools of modern science and technology with applications ranging from medicine [1], to light sources [2], to high-energy physics [3]. Over time, as accelerator-based experiments become more sophisticated and probe natural phenomena with greater temporal resolution, there is an increasing demand on beam parameters, in particular on bunch duration. Experiments have been proposed that require beams with 1-2 orders of magnitude shorter durations than what is possible with current state-of-the-art technology. However, state-of-the-art temporal bunch compressors force a trade-off between how short an electron bunch can be made and how well its transverse quality survives the strong bending MAGNETs required to do so -- a limitation that stands as a grand challenge for accelerator physics to-date [4]. In this experiment, we demonstrate a new, compact compression technique for generating ultrashort, high-peak-current electron bunches that circumvents this trade-off using plasma wakefield acceleration. Just as chirped pulse amplification unlocked ultrashort, high-power LASER pulses and the technologies that followed from them, here we demonstrate an analogous chirp-and-compress strategy applied to RELATIVISTIC electron beams by using the extreme electric fields of a plasma wakefield in place of a stretcher-amplifier, thereby unlocking the path to ultrashort, extremely high-current electron beams. We demonstrate the first application of this plasma-compressed bunch using it to drive single-microbunch free electron lasing at optical wavelengths in a single, meter-scale undulator module, producing radiation pulses roughly four orders of magnitude more energetic than the first beam-driven, plasma-based free electron LASER demonstration at the same accelerator facility [5, 6].
[abstract 42 / 48] (score: 2) - Title: M-SHIVA 1.0: A Relativistic Resistive MHD Code for Heavy-Ion Collisions, with Applications to Momentum Anisotropy and Joule Heating in QGPAuthors: Krishanu Sengupta, Victor Roy,Comments: 32 pages, 16 figures, 4 tablesSubjects: nucl-th hep-ph physics.comp-phCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We present M-SHIVA 1.0 (Magneto-resistive Solver for Heavy Ions with finite-Volume Algorithms), a (2+1)-dimensional RELATIVISTIC resistive MAGNETohydrodynamics code for heavy-ion collisions in Cartesian and boost-invariant Milne coordinates. The present implementation treats inviscid dynamics and employs an implicit-explicit (IMEX) Runge-Kutta scheme for the stiff conductivity-dependent terms, together with complementary primitive-variable recovery procedures and generalized Lagrange multiplier (GLM) divergence cleaning. The code reproduces standard shock-tube, cylindrical-blast-wave and RELATIVISTIC-rotor benchmarks. We use the framework to investigate the momentum anisotropy and electroMAGNETic energy transfer in an expanding QUARK-gluon plasma (QGP). In a controlled elliptic-fireball setup, the electroMAGNETic field modifies the total momentum anisotropy mainly through its direct contribution to the transverse stress tensor, while the matter anisotropy is only weakly affected. We further separate the electroMAGNETic work into mechanical Lorentz-force work and irreversible Joule heating. Applications to Au+Au collisions at $\sqrt{s_{\rm NN}} = 62.4$ and $200$ GeV and Pb+Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV employ optical-Glauber matter profiles, spectator-generated electroMAGNETic fields, and a temperature-dependent electrical conductivity motivated by lattice-QCD results. The ratio of Joule heating to expansion cooling is approximately $10^{-14}$-$10^{-11}$ for Pb+Pb collisions at $2.76$ TeV, $10^{-8}$-$10^{-5}$ for Au+Au collisions at $200$ GeV and $10^{-7}$-$10^{-4}$ at $62.4$ GeV, with no appreciable conductivity dependence of the matter or total momentum anisotropy. Resistive heating thus grows by orders of magnitude with decreasing collision energy but remains negligible compared with longitudinal expansion cooling for all systems considered.
[abstract 43 / 48] (score: 2) - Title: Renormalized dynamical tidal response of neutron stars in binary dynamicsAuthors: M. V. S. Saketh, Raj Patil, Godwin Martin, Nils Andersson, Suprovo Ghosh, Jan Steinhoff,Comments: 20 pages, 5 figures, 1 tableSubjects: gr-qc astro-ph.HE hep-thCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
We present the RELATIVISTIC dynamical tidal response of a neutron star computed using stellar perturbation theory and matched to a worldline effective field theory via the tidal scattering phase. This phase is defined as the difference between the Compton/Raman scattering phase of gravitational-waves from a neutron star and the real part of the BLACK HOLE scattering phase. The gravitational corrections to the response function are obtained using self-energy corrections up to fourth post-Minkowskian order. The response function for neutron stars obeying the BSk22 equation-of-state from Brussels-Skyrme family, is then consistently matched to an effective theory of RELATIVISTIC quadrupolar harmonic oscillators to model the fundamental-mode ($f$-mode) and low-frequency gravity-modes ($g$-modes). This matching includes the frequency and tidal coupling of each mode and the post-adiabatic dynamical tidal Love number, and once matched this model is in excellent agreement with the full neutron star response. With the external tidal field up to third post-Newtonian order, we also analyse the tidal coupling of the induced quadrupole on the neutron star in a circular binary system, and the adiabatic binding energy.
[abstract 44 / 48] (score: 2) - Title: NUSTAR view of the NGC 4151 corona: thermal balance and astroparticle constraintsAuthors: Luigi Foschini,Comments: 15 pages, 4 figures, 3 tablesSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
I present a comprehensive analysis of all publicly available NUSTAR observations of the nearby Seyfert galaxy NGC 4151 (2012--2024). The hard X-ray continuum is well described by thermal Comptonization in a hot corona, with electron temperatures $kT_{\rm e} \approx 40-125$ keV and optical depths $τ\approx 0.4-1.2$ (slab geometry). A clear anti-correlation between $kT_{\rm e}$ and $τ$ is observed, consistent with a thermostat behavior with constant Compton parameter $γ\approx 3.12$ calculated according to Sunyaev and Titarchuk (1980). Variability on timescales of hours constrains the size of the emitting region to $R \approx 250-1200 r_{\rm g}$, corresponding to moderate compactness values $\ell \lesssim 4$. The source occupies the same region of the compactness--temperature plane as other local Seyferts, with no evidence for pair runaway. I then explore two astroparticle implications. The IceCube neutrino excess reported toward NGC 4151 corresponds to $L_ν/L_X \approx 0.3\%$, an energetically negligible contribution that does not alter the observed coronal energy balance. An additional injection of pairs from the hypothetical X17 BOSON cannot produce significant changes, unless the injection rate exceeds the photoproduction one, but no anomalies were found in the present data set. The NUSTAR data thus provide no evidence for either a significant neutrino cooling channel or an X17-related pair injection in the corona of NGC 4151.
[abstract 45 / 48] (score: 2) - Title: Empirical constraints on cosmic-ray scattering in NGC 1333 from dust polarisationAuthors: Szu-Ting Chen, Ellis R. Owen, Alison M. W. Mitchell, Shih-Ping Lai, Sheng-Jun Lin,Comments: 20 pages, 11 figures, 2 tables. Submitted to A&ASubjects: astro-ph.HE astro-ph.GA astro-ph.IMCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Cosmic rays (CRs) regulate molecular-cloud ionization and chemistry. Gyro-resonant scattering by MAGNETic fluctuations sets their mean free path and, on larger scales, their effective diffusion coefficient. However, coefficients inferred from CR distributions averaged over cloud to Galactic scales leave local MAGNETic structure unresolved. We use the MAGNETic-field structure of NGC 1333 and its embedded protostellar core IRAS 4A to estimate local CR scattering rates and effective diffusion coefficients, $D(E)$, and examine their variation with environment and scale. We analyse JCMT/POL-2 maps of nine NGC 1333 regions and ALMA Band 7 maps of two IRAS 4A regions. We estimate plane-of-sky field strengths and derive fluctuation spectra from polarisation-angle structure functions. Where these spectra are sufficiently constrained, we apply quasi-linear gyro-resonant theory to calculate CR pitch-angle scattering rates and $D(E)$. The measured fluctuations constrain CR scattering over proton energy intervals of approximately 0.24-5.3 PeV in NGC 1333 and 10-57 TeV in IRAS 4A. Within these intervals, $D(E)$ spans approximately $3\times10^{28}$-$10^{31}\,{\rm cm^2\,s^{-1}}$. Scattering varies substantially between regions and is stronger where the MAGNETic-field angular dispersion is greater. Extrapolation to common energies suggests scattering in IRAS 4A is one to two orders of magnitude stronger than its surroundings. Within the directly probed intervals, the scattering mean free paths exceed the individual region sizes. The inferred diffusion coefficients therefore characterise local scattering conditions. A cloud-scale diffusive regime requires CRs to sample multiple regions with different scattering rates. Dust polarisation observations therefore provide constraints on CR scattering in clouds, connecting scattering to cloud-scale transport at energies accessible to $γ$-ray observatories.
[abstract 46 / 48] (score: 2) - Title: Spectral-Timing Evolution of the Black Hole X-ray Binary LMC X-3: An XPoSat ViewAuthors: Sayantan Bhattacharya, Aman Kaushik, Sudip Bhattacharyya,Comments: 12 pages, 5 figures, 2 tables. Published in ApJSubjects: astro-ph.HECreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
LMC X-3 is a persistent BLACK HOLE high-mass X-ray binary and serves as an important laboratory for studying accretion disk evolution across different spectral states. We present a spectral-timing analysis of XPoSat/XSPECT observations of LMC X--3 obtained during 2024 and 2025. Using broadband X-ray light curves, hardness diagnostics, power spectral analysis, and spectral modeling, we investigate the long-term evolution of the source across multiple epochs. LMC X-3 exhibits significant changes in both its spectral and timing properties between the two observing campaigns. Hardness-intensity and hardness-rms diagrams reveal a clear separation between the 2024 and 2025 observations and even within the 2024 observations. Overall, it indicates a transition from a relatively harder and more variable state to a brighter, softer, and less variable state. Power spectral analysis shows enhanced broadband variability during the 2024 observations, while the 2025 observations are characterized by weaker variability. Spectral modeling of the combined XSPECT observations indicates an increase in the thermal disk temperature from 0.8 to 1.17 keV, accompanied by a ~5 times increase in X-ray flux between the two epochs. The observed reduction in fractional rms variability with increasing source brightness and decreasing spectral hardness is consistent with more contribution from a stable thermal accretion disk. Taken together, the spectral and timing diagnostics provide a self-consistent picture of accretion-state evolution in LMC X-3, demonstrating the capability of XSPECT to probe long-term variability and accretion processes in bright BLACK HOLE X-ray binaries.
[abstract 47 / 48] (score: 2) - Title: Images of Regular Black Holes with Hedgehog Scalar Hair Embedded in Radiatively Inefficient Accretion FlowsAuthors: Yuxuan Shi, Hao Wei,Comments: 30 pages, 12 figuresSubjects: gr-qc astro-ph.HE hep-thCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
How a BLACK HOLE's geometric critical scale manifests in an accretion-flow image is governed by photon propagation, plasma radiative processes, and instrumental resolution. In this work, we investigate radiatively inefficient accretion flows (RIAF) surrounding geometrically regular BLACK HOLEs with hedgehog scalar hair. Adopting the mass and distance of $\mathrm{M87}^*$, we generate total-intensity SYNCHROTRON images and systematically explore the viewing inclination, disk thickness, and observing frequency. For the fiducial setup at $230\,\mathrm{GHz}$, raising $L/M$ from $0$ to $0.9$ contracts the critical curve diameter by $4.78\%$, shrinks the half-flux radius by $4.07\%$, and lowers the required electron-density scale by $9.15\%$. At $84\,\mathrm{GHz}$, the primary brightness peaks shift farther outside the critical curve due to enhanced SYNCHROTRON self-absorption, whereas the sharper emission rings at $230$ and $345\,\mathrm{GHz}$ closely trace the critical curve. Ultimately, we find that although the regular core systematically contracts the emission ring and alters the required plasma density, resolving these deviations from a Schwarzschild BLACK HOLE demands angular resolution finer than that achievable with current baselines.
[abstract 48 / 48] (score: 2) - Title: New Constraints on the Ultrahigh Energy Neutrino Flux from the First Array-Wide Search with the Askaryan Radio ArrayAuthors: ARA Collaboration, N. Alden, S. Ali, P. Allison, D. Z. Besson, A. Bishop, P. Chen, Y. C. Chen, Y. -C. Chen, S. Chiche, B. A. Clark, A. Connolly, K. Couberly, A. Cummings, P. Dasgupta, K. D. de Vries, C. Deaconu, M. A. DuVernois, J. Flaherty, P. Giri, J. Hanson, K. D. Hoffman, M. -H. Huang, K. Hughes, A. Ishihara, A. Karle, J. L. Kelley, M. -C. Kim, I. Kravchenko, R. Krebs, C. Y. Kuo, U. A. Latif, C. H. Liu, T. C. Liu, W. Luszczak, A. Machtay, M. S. Muzio, J. Nam, R. J. Nichol, A. Novikov, A. Nozdrina, E. Oberla, C. W. Pai, Y. Pan, C. Pfendner, N. Punsuebsay, J. Roth, A. Salcedo-Gomez, D. Seckel, M. F. H. Seikh, Y. -S. Shiao, S. C. Su, S. Toscano, J. Torres, N. van Eijndhoven, A. Vieregg, M. Vilarino Fostier, M. -Z. Wang, S. -H. Wang, P. Windischhofer, S. A. Wissel, S. Yoshida,Comments:Subjects: astro-ph.HE astro-ph.IMCreated: 2026-11-10; Updated: 2026-11-11; Datestamp: 2026-11-11
Ultrahigh energy neutrinos ($E_ν\gtrsim 100$ PeV) are detectable through Askaryan emission---the nanosecond-scale radio impulse emitted by RELATIVISTIC particle cascades in a dielectric medium. The Askaryan Radio Array (ARA), an Askaryan detector array located at the South Pole, has been taking data for more than a decade. We present the first array-wide search for diffuse ultrahigh energy neutrinos with ARA. The search found no events on an expected background of $0.13\pm0.01\text{ (stat.)}^{+0.05}_{-0.06}\text{ (syst.)}$ events. The resulting upper limit is the most stringent from $50$ EeV to $1000$ EeV and provides the first constraints on the flux reported by the KM3NeT Collaboration that are complementary to optical Cherenkov and particle detectors. This limit also constrains UHECR source models, and excludes some models with trans-GZK proton populations at the $90\%$ confidence level. This represents the largest Askaryan detector dataset ever analyzed, demonstrating the feasibility and sensitivity of searches with large detector arrays acting as a single observatory. It also underscores the high acceptance and exposure of Askaryan detector arrays to ultrahigh energy neutrinos.
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