Fast Radio Burst Localisation and Followup with CHIME/FRB and GMRT

Fast Radio Bursts (FRBs) are very energetic extragalactic transient astronomical events. The observations of FRBs using many radio telescopes around the world have revealed that some FRBs repeat, while others are apparently one-off. Even for those that repeat, most sources do not emit bursts at predictable intervals. It is still an open question as to what causes such bright emission. To tackle this problem of uncovering the progenitors of FRBs, we need to detect as many sources as possible, localise them to their parent galaxies, and study the local environments of these events. The Canadian Hydrogen Intensity Mapping Experiment (CHIME), is a transit radio telescope in Canada that scans large portions of the sky daily to detect FRBs. CHIME has detected close to 4000 FRBs which includes about 30 repeating sources. The CHIME collaboration is building smaller CHIME- like “outrigger” telescopes in three locations spread across North America to aid in better localisation of FRBs. Two of the outrigger telescopes, one in Allenby, British Columbia (about 100 km from CHIME main site), and another in the Green Bank Observatory in West Virginia, USA (about 3300 km from CHIME) have already been built and are currently in the commissioning phase. These outrigger telescopes will be crucial in making very long baseline interferometry (VLBI) observations to pinpoint locations of FRBs in the sky. Over the past year I have worked on commissioning and calibration diagnostics of these newly constructed outrigger telescopes. I will discuss the calibration methods developed for regularly spaced arrays, the challenges faced in consistent calibration, and the results. In addition to this, I am undertaking deep uGMRT observations to study the persistent radio emission from two already localised repeating FRBs to understand their nature. I will present preliminary results from our findings in this talk.