Spectral study of sample of GeV emission gamma-ray bursts with quiescent episodes

Abstract

Gamma-ray bursts, or GRBs, are the most energetic phenomena in the universe that may occur as a result of mergers between compact objects and supernova explosions. While many GRBs are characterized by having a single emission peak, a few have been found to occur with multiple peaks having potential emission gaps dubbed “quiescent episodes.” While the occurrence of such intervals remains in debate, the spectral study of these GRBs can provide an insight about the evolution of parameters within different peaks of the same GRB. We have performed the time-resolved analysis of a sample of four GRBs having emission in both the GBM and LAT range. These GRBs were selected based on a particular criteria. We have also studied the evolution of spectral parameters and tested each interval for the Amati Correlation through the E_iso and E_i,peak relations. We have found the individual peaks to fit with simple models. The low-energy index was typically found to evolve with a hard-to-soft spectrum. The flux indicates a decay in time, while peak energy evolution may reveal different trends. One of the GRBs in our sample with a potential precursor emission seems to evolve differently than the rest of the GRBs in the sample.