Degree
Doctor of Philosophy (PhD)
Department
Physics & Astronomy
Document Type
Dissertation
Abstract
Magnetar giant flares are rare, extremely bright bursts of gamma-rays from highly magnetized neutron stars. These events are difficult to identify because, at extragalactic distances, they can appear similar to other astrophysical phenomena. Only a handful have been confidently identified to date, limiting our understanding of their origin and physical properties. This dissertation focuses on expanding the sample of known events and enabling a more detailed characterization of their observational features. We report on two newly identified examples, GRB 180128A and GRB 231115A, that are consistent with a magnetar origin based on their spectral properties and association with nearby star-forming galaxies.
We introduce significant improvements in the methods applied to identify and characterize these events. Applying this to archival data helped us increase the known sample of seven by almost a factor of two. This demonstrates that the method is effective and that additional magnetar giant flares likely remain unidentified in existing gamma-ray burst catalogs. We utilize this expanded sample to gain a deeper understanding of the broader population of magnetar giant flares. We develop a statistical modeling framework that combines older data with modern observations from the Gamma-ray Burst Monitor on the Fermi Gamma-ray Space Telescope. The model accounts for instrumental sensitivity and the expected diversity in event characteristics. By simulating detectability across instruments, we estimate the frequency of these events and the variation in their observable features, yielding the most robust and well-constrained population estimates to date. The results suggest that individual magnetars must produce multiple flares throughout their lifetimes, reinforcing the idea that these are recurring phenomena rather than singular explosive events. Expanding the sample of known magnetar giant flares will improve our understanding of magnetars and their role in other astrophysical phenomena, including possible links to fast radio bursts, gravitational waves, and the creation of heavy elements in extreme astrophysical environments.
Date
7-11-2025
Recommended Citation
Trigg, Aaron, "THE SEARCH FOR MAGNETAR GIANT FLARES IN ARCHIVAL GAMMA-RAY BURST DATA TO CONSTRAIN THEIR RATES AND ENERGETICS" (2025). LSU Doctoral Dissertations. 6854.
https://repository.lsu.edu/gradschool_dissertations/6854
Committee Chair
Eric Burns
DOI
10.31390/gradschool_dissertations.6854