242.10 Seeking Fast Radio Burst Origins Using the Very Large Array (Bridget Clare Andersen)

Date & Time

Jan 5th at 5:30 PM until 6:30 PM




Rating ( votes)

Author(s): Bridget Clare Andersen2, Sarah Spolaor1, Paul Demorest1

Institution(s): 1. National Radio Astronomy Observatory, 2. University of Virginia

Contributing team(s): Realfast

Fast radio bursts (FRBs) are transient pulses of radio emission lasting on the order of milliseconds. There have been ~25 FRB sources discovered to date with pulse widths ranging from 1 to 15 ms, and flux densities typically ranging from 0.3 to 2.0 Jy (Petroff et al. 2016). These FRBs have dispersion measures (DMs) on the order of hundreds of pc/cc, well in excess of the expected Galactic contribution. This has lead many to believe that FRBs are extragalactic in origin, with leading progenitor theories suggesting some connection to neutron star related events. However, plausible origin theories remain numerous (Popov & Pshirkov 2016). Thus, localization will be a critical contribution to our understanding of FRBs. Spatial identification of a progenitor would not only help us whittle down origin theories but also allow us to utilize FRBs as invaluable cosmological probes of the intergalactic medium. All reported FRBs to date have been discovered with single dish telescopes that have insufficient resolution for confident localization. In contrast, the Very Large Array (VLA) has the capability to detect and localize FRBs to arcsecond precision. Project realfast takes advantage of this unique localization capability to conduct FRB searches at the VLA in quasi-real-time. We present recent realfast data, including the development of FRB visualization using interferometric imaging, and a discussion of thermal noise candidates and common types of radio frequency interference detected by realfast software. We also present the results of the FRB candidate search for the most recent 150 hour VLA observing campaign. This campaign focused on observations of nearby galaxies with high star-formation rates, and we are thus able to perform a sharp test on any correlation between FRB rates and star-forming galaxies, as might be expected if FRBs originate from neutron stars in nearby galaxies. This analysis allows us to put a lower limit on the characteristic distance to FRBs.