Abstract Details
| Name: Kuntal Misra Affiliation: ARIES Conference ID: ASI2018_704 Title : Merger ejecta in short gamma ray bursts Authors and Co-Authors : L. Resmi (IIST, Thiruvanthapuram) K. G. Arun (CMI, Chennai) Abstract Type : Contributed Talk Abstract Category : Extragalactic astronomy Abstract : The most probable progenitors of short duration gamma ray bursts (GRB) are believed to be the merger binary compact object systems comprising of either two neutron stars (BNS) or a neutron star and a black hole (NS-BH). The recent detection of GRB 170817A from the binary neutron star merger GW 170817 has strengthened this progenitor scenario. In addition to the ultra-relativistic jet, which produces the GRB, numerical simulations have indicated other kind of mass ejection during the merger. The mass thrown out with sub-relativistic velocities during the tidal disruption of the neutron star is the most promising observational signature. The tidal ejecta undergoes r-process nucleosynthesis and produces NIR emission resulting in a ‘kilonova’. At these velocities, apart from the kilonova emission, the ejecta is also expected to be visible in radio frequencies over a time scale of a few years. The peak of this spectrum lies in MHz frequencies. We present our preliminary results for the search of merger ejecta from two short GRBs with the GMRT at 610 and 325 MHz. Our observations put tight constraints on the magnetar rotation energy. |