Luminosity correlation in GRBs: further insights and implications for Cosmology
Il giorno venerdì 4 ottobre 2019, alle ore 10.00 in Aula 2N40 il Dr. Disha Sawant, University of Bombay, India terrà un seminario intitolato:
"Time resolved Ep,i - Luminosity correlation in GRBs: further insights and implications for Cosmology"
Abstract
The correlation between the spectral peak energy (Ep,i) and radiated energy (Eiso) or luminosity (Liso) is one of the main properties of the prompt emission of GRBs, with relevant implications for emission physics, jet structure and the use of these phenomena for measuring cosmological parameters. Time–resolved spectral analyses of BATSE, BeppoSAX and Fermi samples have shown that this correlation holds also within single GRBs, providing evidence for its physical origin and its reliability. In this article, based on the time–resolved spectral analysis of a sample of Fermi GRBs with measured redshift as of the end of 2014 (for a total of more than 1000 spectra), we provide further insight in the characterization of the time–resolved Ep,i – Liso correlation, discuss its main consequences and investigate the connection between time–resolved and time–averaged or time–integrated Ep,i–intensity correlations. In particular, we find evidence that: a) the scatter of the Ep,i(t)–Liso(t) within single GRBs is half of that of the Ep,i(t)–Liso(t) correlation obtained with all spectra of all GRBs and that of the time–averaged (Ep,i – Liso ) or time–integrated (Ep,i – Eiso ) correlations; b) the slope of the Ep,i(t)–Liso(t) correlation within single GRBs is ∼0.5, i.e., the same as that of the "global" and time–averaged (integrated) correlations; c) the time–averaged (integrated) correlations obtained by computing Ep,i and Liso(Eiso) based on the results of the time–resolved analysis of each single GRBs are slightly tighter than those derived by using time–averaged (integrated) spectra. We also discuss the cosmological implications of the correlation particularly in obtaining a constraint on the matter density parameter and the future prospects.
Data:
04/10/2019