11 papers
A Search for GeV Emission from Magnetar Giant Flare Candidates with Fermi-LAT
Vikas Chand, Michela Negro, Nicola Omodei +5
The discovery of delayed GeV emission from the extragalactic magnetar giant flare (MGF) GRB 200415A, located in the nearby Sculptor galaxy, revealed for the first time that these r…
Polarization of reflected X-ray emission from the Sgr A molecular complex: multiple flares, multiple sources?
Ildar Khabibullin, Eugene Churazov, Riccardo Ferrazzoli +100
The extended X-ray emission observed in the direction of several molecular clouds in the central molecular zone of our Galaxy exhibits spectral and temporal properties consistent w…
Super-Eddington Accretion Geometry: a Remarkable Stability of the Hidden Ultraluminous X-Ray Source Cygnus X-3
Romana Mikušincová, Alexandra Veledina, Fabio Muleri +112
We report on the average and orbital phase-resolved polarization of Cyg X-3 in the hard state during the 2023 Imaging X-ray Polarimetry Explorer (IXPE) observational campaign. We f…
From Rare Events to a Population: Discovering Overlooked Extragalactic Magnetar Giant Flare Candidates in Archival Fermi Gamma-ray Burst Monitor Data
Aaron C. Trigg, Eric Burns, Michela Negro +16
Magnetar giant flares (MGFs) are rare, extremely bright bursts of gamma-rays from highly magnetized neutron stars. These events are challenging to identify because, at extragalacti…
X-ray Polarization Detection of the Pulsar Wind Nebula in G21.5-0.9 with IXPE
Niccolò Di Lalla, Nicola Omodei, Niccolò Bucciantini +98
We present the X-ray polarization observation of G21.5-0.9, a young Galactic supernova remnant (SNR), conducted with the Imaging X-ray Polarimetry Explorer (IXPE) in October 2023,…
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…