GLAST Prospects for Swift-Era Afterglows

TL;DR

This paper models the GeV spectra of GRB afterglows using improved parameters and recent Swift data, assessing detectability limits for GLAST LAT and AGILE.

Contribution

It introduces refined modeling of GRB afterglows incorporating recent Swift observations and explores detection prospects with current gamma-ray telescopes.

Findings

Time-dependent GeV spectra for various models

Detection limits up to certain redshifts for GLAST LAT and AGILE

Impact of energy injection and parameter evolution on spectra

Abstract

We calculate the GeV spectra of GRB afterglows produced by inverse Compton scattering of the sub-MeV emission of these objects. We improve on earlier treatments by using refined afterglow parameters and new model developments motivated by recent Swift observations. We present time-dependent GeV spectra for standard, constant parameter models, as well as for models with energy injection and with time-varying parameters, for a range of burst parameters. We evaluate the limiting redshift to which such afterglows can be detected by the GLAST LAT, as well as AGILE.