Uncovering the nature of Fast Radio Bursts through multi-wavelength studies

Fast Radio Bursts (FRBs) are millisecond-timescale radio transients originating from cosmological distances (~Gpc) that have been discovered a little more than a decade ago. At these distances, they have to be a trillion times more luminous than the brightest radio pulses observed from Galactic pulsars. The engine and emission mechanism that can produce such luminosities is still unknown despite ~80 different theories. Over the past few years, the Canadian Hydrogen Intensity Mapping Experiment (CHIME) FRB backend has detected hundreds of FRBs including a dozen repeating FRBs and a  few of the nearest FRB sources. The repeating nature of these FRBs, allows for precise localization with radio interferometers and a detailed study of their environment and nature with multi-wavelength observations. I will introduce the broad questions about the nature of FRBs and their promise as tools for cosmology. I will focus on discussing recent multi-wavelength  results on two of the best studied FRBs — FRB 121102 and FRB 180916 — from CHIME/FRB as well as a larger collaboration which shed new light on the nature of these sources.