Joint spectral analysis of GRBs, a time-resolved systematic approach

Summary. — The Fermi mission is a space-based observatory designed to study the gamma-ray sky. It comprises two main instruments: the Large Area Telescope (LAT) and the Gamma-ray Burst Monitor (GBM), together covering a broad energy range from approximately 10 keV to over 300 GeV. One of the mission’s key scientific goals is the detection and study of Gamma-Ray Bursts (GRBs), whose prompt emission mechanisms and emission sites remain not fully understood. In this work, we focus on bright GRBs observed jointly by Fermi-GBM and FermiLAT. Two fully operational pipelines, developed using the Multi-Mission Maximum Likelihood (3ML) framework, have been implemented to perform systematic joint spectral analyses-both time-integrated and time-resolved. These tools have been tested on a sample of approximately 50 GRBs; from these analyses, we obtained preliminary distributions of spectral parameters, such as photon indices, peak energy, and possible additional components. This work sets the stage for a broader systematic study leveraging Fermi’s broadband capabilities.