Correlative Spectral Analysis of Gamma-Ray Bursts using Swift-BAT and GLAST-GBM

TL;DR

This paper discusses the potential of joint spectral analysis of gamma-ray bursts using Swift-BAT and GLAST-GBM to enhance calibration, sensitivity, localization, and scientific understanding of GRB emissions over multiple energy ranges.

Contribution

It introduces a framework for combined spectral analysis of GRBs with Swift-BAT and GLAST-GBM, highlighting benefits for calibration, sensitivity, localization, and broad-band spectral studies.

Findings

Joint spectral fits can improve GRB characterization.

Enhanced low-energy sensitivity aids in detecting more GRBs.

Multi-wavelength analysis enables studying spectral evolution.

Abstract

We discuss the preliminary results of spectral analysis simulations involving anticipated correlated multi-wavelength observations of gamma-ray bursts (GRBs) using Swift's Burst Alert Telescope (BAT) and the Gamma-Ray Large Area Space Telescope's (GLAST) Burst Monitor (GLAST-GBM), resulting in joint spectral fits, including characteristic photon energy (Epeak) values, for a conservative annual estimate of ~30 GRBs. The addition of BAT's spectral response will (i) complement in-orbit calibration efforts of GBM's detector response matrices, (ii) augment GLAST's low energy sensitivity by increasing the ~20-100 keV effective area, (iii) facilitate ground-based follow-up efforts of GLAST GRBs by increasing GBM's source localization precision, and (iv) help identify a subset of non-triggered GRBs discovered via off-line GBM data analysis. Such multi-wavelength correlative analyses, which have been demonstrated by successful joint-spectral fits of Swift-BAT GRBs with other higher energy detectors such as Konus-WIND and Suzaku-WAM, would enable the study of broad-band spectral and temporal evolution of prompt GRB emission over three energy decades, thus potentially increasing the science return without placing additional demands upon mission resources throughout their contemporaneous orbital tenure over the next decade.