| Abstract : | The discovery Fast Radio Bursts (FRBs), the millisecond-duration, bright and energetic events observed from the distant universe, has heralded a new era in time-domain astronomy. They have become an object of serious research in the last decade or so, throwing up many questions about their astrophysical origins. Their extragalactic origin, now firmly established, has opened the possibility of using FRBs as probes of the intervening medium, both local to their host galaxies, as well as the ISM of the Milky Way through which they are viewed. Repeating FRBs provide us with the opportunity to study them in depth through detailed follow-up observations. While instruments like CHIME, ASKAP and DSA are designed for efficient FRB surveys, deep follow-up observations benefit from sensitive telescopes like the GMRT. At the GMRT, we have been following up a few repeating FRBs for detailed investigation: in particular, we have used the GMRT for arc-second level localization as a proof-of-concept, as well as detecting the weakest bursts at frequencies < 1.5 GHz, important for bridging the energy gap between FRBs and Galactic magnetars, which are being proposed as possible progenitors. Besides empirical studies, investigation of polarization, propagation effects and any putative persistent radio emission offers a handle to glean the local environments of FRBs, which may have a direct bearing on their origins. FRBs function as an excellent probe of the Milky Way and the halo ISM, in addition to the local ISM of the host galaxy, manifesting as different effects such as Faraday rotation, scatter broadening and scintillation. I will emphasize some of the results we have obtained using the upgraded GMRT, by measuring the polarization, scintillation and scattering of a few FRBs in the recent past and motivate the need for continued follow-up of repeaters at low frequencies. |
