Energetic Fermi/LAT GRB100414A: Energetic and Correlations

TL;DR

This paper reports multi-wavelength observations of the energetic GRB100414A, highlighting its spectral properties, optical afterglow behavior, and correlations with known GRB relations, suggesting a supernova association.

Contribution

First detailed multi-wavelength analysis of Fermi/LAT detected GRB100414A, including spectral fitting, afterglow modeling, and correlation verification, with evidence of a supernova component.

Findings

Spectral peak energy of 1458.7 keV and isotropic energy of 3.45 x 10^52 erg.

Optical afterglow shows a temporal break at 2.3 days, indicating jet opening angle of 5.8 degrees.

Late afterglow excess suggests association with a supernova.

Abstract

This study presents multi-wavelength observational results for energetic GRB100414A with GeV photons. The prompt spectral fitting using Suzaku/WAM data yielded spectral peak energies of E^src_peak of 1458.7 (+132.6, -106.6) keV and Eiso of 34.5(+2.0, -1.8) x 10^52 erg with z=1.368. The optical afterglow light curves between 3 and 7 days were effectively fitted according to a simple power law with a temporal index of alpha=-2.6 +/- 0.1. The joint light curve with earlier Swift/UVOT observations yields a temporal break at 2.3 +/- 0.2 days. This was the first \fermi/LAT detected event that demonstrated the clear temporal break in the optical afterglow. The jet opening angle derived from this temporal break was 5.8 degree, consistent with those of other well-observed long gamma-ray bursts (GRBs). The multi-wavelength analyses in this study showed that GRB100414A follows E^src_peak-Eiso and E^src_peak-E_gamma correlations. The late afterglow revealed a flatter evolution with significant excesses at 27.2 days. The most straightforward explanation for the excess is that GRB100414A was accompanied by a contemporaneous supernova. The model light curve based on other GRB-SN events is marginally consistent with that of the observed lightcurve.