Extragalactic magnetar giant flare GRB 231115A: Insights from <i>Fermi</i>/GBM observations
Magnetar giant flares (MGFs) are the extremely short, energetic transients originating from highly magnetized neutron stars. When observed in nearby galaxies, these rare events are nearly indistinguishable from cosmological short gamma-ray bursts. We present the analysis of GRB 231115A, a candidate extragalactic MGF observed by Fermi /GBM and localized by INTEGRAL to the starburst galaxy M82. This burst exhibits distinctive temporal and spectral characteristics, including a short duration and a high peak energy, consistent with known MGFs. Time-resolved analysis reveals rapid spectral evolution and a clear correlation between luminosity and spectral hardness, providing robust evidence of relativistic outflows. Archival Chandra data identified point sources within the GRB 231115A localization consistent with the theoretical maximum persistent emission luminosity, though no definitive counterpart was found. Simulations indicate that any transient emission associated with GRB 231115A would require energies exceeding those of typical magnetar bursts to be detectable by current instruments. While the tail of a MGF originating from outside of the Milky Way and its satellite galaxies has never been detected, analysis suggests that such emission could be observable at M82’s distance with instruments like Swift /XRT or NICER, though no tail was identified for this event. These findings underscore the need for improved follow-up strategies and technological advancements to enhance MGF detection and characterization.
Authors
- M. S. Briggs (ORCID: https://orcid.org/0000-0003-2105-7711)
- George Younes (ORCID: https://orcid.org/0000-0002-7991-028X)
- C. Kouveliotou (ORCID: https://orcid.org/0000-0003-1443-593X)
- D. Gruen (ORCID: https://orcid.org/0000-0003-3270-7644)
- R. J. Stewart (ORCID: https://orcid.org/0000-0002-0254-5915)
- L. Scotton (ORCID: https://orcid.org/0000-0002-0602-0235)
- O. J. Roberts (ORCID: https://orcid.org/0000-0002-7150-9061)
- Zorawar Wadiasingh (ORCID: https://orcid.org/0000-0002-9249-0515)
- D. Frederiks (ORCID: https://orcid.org/0000-0002-1153-6340)
- A. Trigg (ORCID: https://orcid.org/0009-0006-8598-728X)
- P. Vereš (ORCID: https://orcid.org/0000-0002-2149-9846)
- A. Palmese (ORCID: https://orcid.org/0000-0002-6011-0530)
- Brendan O’Connor (ORCID: https://orcid.org/0000-0002-9700-0036)
- D. Svinkin (ORCID: https://orcid.org/0000-0002-2208-2196)
- Michela Negro (ORCID: https://orcid.org/0000-0002-6548-5622)
- A. Goldstein (ORCID: https://orcid.org/0000-0002-0587-7042)
- Raphael Zöller
- Eric Burns (ORCID: https://orcid.org/0000-0002-2942-3379)
- Matthew G. Baring (ORCID: https://orcid.org/0000-0003-4433-1365)
- Lei Hu (ORCID: https://orcid.org/0000-0002-0547-6265)
- Malte Busmann (ORCID: https://orcid.org/0009-0001-0574-2332)
- Daniela Huppenkothen
- Arno Riffeser
- Narayana R. Bhat
- Alex van Kooten
Institutions
- Louisiana State University (US)
- Goddard Space Flight Center (US)
- Universities Space Research Association (US)
- George Washington University (US)
- Max Planck Institute for Extraterrestrial Physics (DE)
- Excellence Cluster Origins (DE)
- Science and Technology Corporation (United States) (US)
- Deleted Institution
- Space Research Organisation Netherlands (NL)
- University of Maryland, College Park (US)
- Rice University (US)
- Carnegie Mellon University (US)
- Ludwig-Maximilians-Universität München (DE)
- University of Alabama in Huntsville (US)
- Ioffe Institute (RU)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2025-02-01
- DOI
- https://doi.org/10.1051/0004-6361/202452268
- Citations
- 2
- Primary Topic
- Gamma-ray bursts and supernovae
- Type
- article
- Field-Weighted Citation Impact
- 2.31
Funders
- National Aeronautics and Space Administration
- Carnegie Mellon University
- Universities Space Research Association
- Deutsche Forschungsgemeinschaft
- Nuclear Safety and Security Commission
- Ioffe Institute
- Goddard Space Flight Center