The Progenitors of Fast Radio Bursts

Citation

Bochenek, Christopher David (2021) The Progenitors of Fast Radio Bursts. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/7tsx-x524. https://resolver.caltech.edu/CaltechTHESIS:05192021-014425301

Abstract

Fast radio bursts (FRBs) are millisecond duration pulses of radio emission that are bright enough to be seen from other galaxies. The nature of the objects that produce fast radio bursts has captivated the interest of astronomers since their discovery in 2007. The durations and energetics of FRBs imply a compact, highly magnetized progenitor, making magnetars a popular progenitor candidate. However, it is difficult to pin down the progenitors of FRBs because they occur so far away. In this thesis, I will present the Survey for Transient Astronomical Radio Emission 2 (STARE2), an experiment designed to detect FRBs in the Milky Way. I will present a formalism through which to interpret the results of this experiment and demonstrate our experiment's effectiveness with the detection of a solar burst. Using STARE2, we discovered the first FRB that originated within the Milky Way, FRB 200428. This FRB was traced back to the Galactic magnetar SGR J1935+2154. The energetics, spectro-temporal properties, host galaxy, environment, and X-ray counterpart are all consistent with the properties of extragalactic FRBs. In addition, the high volumetric rate of these bright radio bursts from magnetars is consistent with the volumetric rate of FRBs, implying that magnetars are the dominant channel of FRB production. I will then develop a novel statistical technique to compare transient host galaxies in order to evaluate whether the hosts of extragalactic FRBs are consistent with a magnetar origin. I will find that the hosts of FRBs are consistent with the hosts of core-collapse supernovae, supporting the hypothesis that magnetars produce FRBs. Finally, I will present two ideas for future observing campaigns to find FRBs from M82 and more extremely bright pulses from Galactic magnetars.

Thesis Files