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19922026
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171 papers · 1 filter

astro-ph.HE2026

Refined Constraints on the Hard X-ray Polarization of the Crab Pulsar and Nebula Derived from an Extended XL-Calibur Dataset

Matthew G. Baring, Jacob Casey, Sohee Chun +26

We present updated hard X-ray polarization measurements of the Crab pulsar and nebula obtained with the balloon-borne polarimeter XL-Calibur in the ~19-64 keV energy range. During…

astro-ph.HE2026

GRRMHD Simulations of State Transitions in Non-Jetted Tidal Disruption Events

Brandon Curd, Safira Heridia, Aviyel Ahiyya +1

Circularization of the stream material into a debris cloud during tidal disruption events (TDEs) was recently demonstrated in one of the most accurate long duration TDE simulations…

astro-ph.HE2026★ 1 cited

Locating the missing large-scale emission in the jet of M87* with short EHT baselines

Boris Georgiev, Paul Tiede, Sebastiano D. von Fellenberg +280

In Very-Long Baseline Interferometric arrays, nearly co-located stations probe the largest scales and typically cannot resolve the observed source. In the absence of large-scale st…

astro-ph.HE2025★ 1 cited

Pulsed, Polarized X-ray Emission from Neutron Star Surfaces: the Effects of Vacuum Birefringence in the Magnetosphere

Hoa Dinh Thi, Matthew G. Baring, Kun Hu +4

Intense magnetic fields in the atmospheres of neutron stars render non-trivial angular dependence of intensity and polarization of soft X-ray emission originating from their surfac…

astro-ph.HE2025★ 4 cited

Probing jet base emission of M87* with the 2021 Event Horizon Telescope observations

Saurabh, Hendrik Müller, Sebastiano D. von Fellenberg +282

We investigate the presence and spatial characteristics of the jet base emission in M87* at 230 GHz, enabled by the enhanced uv coverage in the 2021 Event Horizon Telescope (EHT) o…

astro-ph.HE2025★ 20 cited

Horizon-scale variability of M87* from 2017--2021 EHT observations

The Event Horizon Telescope Collaboration

We report three epochs of polarized images of M87* at 230\,GHz using data from the Event Horizon Telescope (EHT) taken in 2017, 2018, and 2021. The baseline coverage of the 2021 ob…

astro-ph.HE2025★ 4 cited

Vacuum birefringence and the polarized X-ray emission from a radio magnetar

Rachael E. Stewart, Hoa Dinh Thi, George Younes +13

Magnetars are isolated neutron stars with exceptionally strong surface fields exceeding G. Their bright X-ray emission probes physical regimes in which quantum electrodyn…

astro-ph.HE2025★ 3 cited

Monte Carlo Simulations of Polarized Radiative Transfer in Neutron Star Atmospheres

Hoa Dinh Thi, Matthew G. Baring, Kun Hu +2

Soft X-ray emission from neutron stars affords powerful diagnostic tools for uncovering their surface and interior properties, as well as their geometric configurations. In the atm…

astro-ph.HE2025★ 6 cited

Crust (Unified) Tool for Equation-of-state Reconstruction (CUTER) v2

P. J. Davis, H. Dinh Thi, A. F. Fantina +3

The equation of state (EoS) is a needed input to determine the neutron-star global properties and to relate them. It is thus important to provide consistent and unified EoSs to avo…

astro-ph.HE2025★ 4 cited

Origin of the ring ellipticity in the black hole images of M87*

Rohan Dahale, Ilje Cho, Kotaro Moriyama +273

We investigate the origin of the elliptical ring structure observed in the images of the supermassive black hole M87*, aiming to disentangle contributions from gravitational, astro…

astro-ph.HE2025★ 5 cited

XL-Calibur measurements of polarised hard X-ray emission from the Crab

Hisamitsu Awaki, Matthew G. Baring, Richard Bose +46

We report measurements of the linear polarisation degree (PD) and angle (PA) for hard X-ray emission from the Crab pulsar and wind nebula. Measurements were made with the XL-Calibu…

astro-ph.HE2025

Timing and Spectral Evolution of the Magnetar 1E 1841-045 in Outburst

G. Younes, S. K. Lander, M. G. Baring +19

We present the timing and spectral analyses of the NICER, NuSTAR, and IXPE observations of the magnetar 1E 1841-045 covering 82 days following its August 2024 bursting activity as…

astro-ph.HE2025★ 10 cited

The putative center in NGC 1052

Anne-Kathrin Baczko, Matthias Kadler, Eduardo Ros +284

Many active galaxies harbor powerful relativistic jets, however, the detailed mechanisms of their formation and acceleration remain poorly understood. To investigate the area of je…

astro-ph.HE2024

X-ray polarization of the magnetar 1E 1841-045

Rachael Stewart, George A. Younes, Alice K. Harding +15

We report on IXPE and NuSTAR observations beginning forty days after the 2024 outburst onset of magnetar 1E 1841-045, marking the first IXPE observation of a magnetar in an enhance…

astro-ph.HE2024★ 1 cited

Pulsed and Polarized X-ray Emission from Neutron Star Surfaces

Matthew G. Baring, Hoa Dinh Thi, George A. Younes +1

The intense magnetic fields of neutron stars naturally lead to strong anisotropy and polarization of radiation emanating from their surfaces, both being sensitive to the hot spot p…

astro-ph.HE2024★ 5 cited

Extragalactic Magnetar Giant Flare GRB 231115A: Insights from Fermi/GBM Observations

Aaron C. Trigg, Rachael Stewart, Alex Van Kooten +22

We present the detection and analysis of GRB 231115A, a candidate extragalactic magnetar giant flare (MGF) observed by Fermi/GBM and localized by INTEGRAL to the starburst galaxy M…

astro-ph.HE2024★ 4 cited

Concise Spectrotemporal Studies of Magnetar SGR J1935+2154 Bursts

Ozge Keskin, Ersin Gogus, Yuki Kaneko +6

SGR J1935+2154 has truly been the most prolific magnetar over the last decade: It has been entering into burst active episodes once every 1-2 years since its discovery in 2014, it…

astro-ph.HE2024★ 30 cited

Rapid spin changes around a magnetar fast radio burst

Chin-Ping Hu, Takuto Narita, Teruaki Enoto +12

Magnetars are neutron stars with extremely high magnetic fields that exhibit various X-ray phenomena such as sporadic sub-second bursts, long-term persistent flux enhancements, and…

astro-ph.HE2023★ 5 cited

GRB 180128A: A Second Magnetar Giant Flare Candidate from the Sculptor Galaxy

Aaron C. Trigg, Eric Burns, Oliver J. Roberts +14

Magnetars are slowly rotating neutron stars that possess the strongest magnetic fields () known in the cosmos. They display a range of transient high-en…

astro-ph.HE2023★ 169 cited

The Third Fermi Large Area Telescope Catalog of Gamma-ray Pulsars

David A. Smith, Philippe Bruel, Colin J. Clark +156

We present 294 pulsars found in GeV data from the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope. Another 33 millisecond pulsars (MSPs) discovered in deep radio…

astro-ph.HE2023★ 5 cited

Quasi-Periodic Peak Energy Oscillations in X-ray Bursts from SGR J1935+2154

Oliver J. Roberts, Matthew G. Baring, Daniela Huppenkothen +6

Magnetars are young neutron stars powered by the strongest magnetic fields in the Universe (10 G). Their transient X-ray emission usually manifests as short (a few hundre…

astro-ph.HE2023★ 143 cited

Fermi-GBM Discovery of GRB 221009A: An Extraordinarily Bright GRB from Onset to Afterglow

S. Lesage, P. Veres, M. S. Briggs +136

We report the discovery of GRB 221009A, the highest flux gamma-ray burst ever observed by the Fermi Gamma-ray Burst Monitor (GBM). This GRB has continuous prompt emission lasting m…

astro-ph.HE2023★ 20 cited

The 2022 high-energy outburst and radio disappearing act of the magnetar 1E 1547.0-5408

Marcus E. Lower, George Younes, Paul Scholz +19

We report the radio and high-energy properties of a new outburst from the radio-loud magnetar 1E 1547.05408. Following the detection of a short burst from the source with Swift-…

astro-ph.HE2022★ 1 cited

Morphology of Shocked Lateral Outflows in Colliding Hydrodynamic Flows

R. N. Markwick, A. Frank, J. Carroll-Nellenback +6

Supersonic interacting flows occurring in phenomena such as protostellar jets give rise to strong shocks, and have been demonstrated in several laboratory experiments. To study suc…