Fast Radio Burst Localization with the CHIME/FRB Outrigger system

Adam Lanman
McGill University

Abstract

Fast radio bursts (FRBs) are micro to millisecond duration flashes of radio emission whose high dispersion indicates extra-Galactic origins. Their sources are not yet fully understood, though several plausible models have been proposed. As compact transients visible at cosmological distances, FRBs have the potential to serve as powerful probes of the intergalactic medium (IGM), as the frequency dispersion of the pulse depends on the density and ionization state of the plasma it travels through. The FRB program of the Canadian Hydrogen Intensity Mapping Experiment (CHIME/FRB) has become the leading instrument for detecting FRBs, releasing a catalog of 536 new FRB sources in 2021 and detecting, on average, a new candidate every day. Although CHIME/FRB has excellent characteristics for detecting FRBs, it lacks the sub-arcsecond resolution required to identify their host galaxies. Three new outrigger antennas — one near CHIME in British Columbia, one in the Green Bank Observatory in West Virginia, and one in the Hat Creek Observatory in California — will enable CHIME to perform very long baseline interferometry (VLBI) on FRB candidates at detection, effectively combining the discovery rate of CHIME with the resolution of VLBI. In this talk, I will discuss the CHIME/FRB Outrigger program, current accomplishments in performing VLBI on radio transients, and the prospects of using localized FRBs to study the cosmic evolution of the intergalactic medium