154 research outputs found
Simulation of prompt emission from GRBs with a photospheric component and its detectability by GLAST
The prompt emission from gamma-ray bursts (GRBs) still requires a physical
explanation. Studies of time-resolved GRB spectra, observed in the keV-MeV
range, show that a hybrid model consisting of two components, a photospheric
and a non-thermal component, in many cases fits bright, single-pulsed bursts as
well as, and in some instances even better than, the Band function. With an
energy coverage from 8 keV up to 300 GeV, GLAST will give us an unprecedented
opportunity to further investigate the nature of the prompt emission. In
particular, it will give us the possibility to determine whether a photospheric
component is the determining feature of the spectrum or not. Here we present a
short study of the ability of GLAST to detect such a photospheric component in
the sub-MeV range for typical bursts, using simulation tools developed within
the GLAST science collaboration.Comment: 12 pages, 5 figures; submitted proceeding for GRB Symposium in
Stockholm, Sweden : "Gamma-Ray Bursts: Prospects for GLAST
The GLAST mission, LAT and GRBs
The GLAST Large Area Telescope (LAT) is the next generation satellite
experiment for high-energy gamma-ray astronomy. It is a pair conversion
telescope built with a plastic anticoincidence shield, a segmented CsI
electromagnetic calorimeter, and the largest silicon strip tracker ever built.
It will cover the energy range from 30 MeV to 300 GeV, shedding light on many
issues left open by its predecessor EGRET. One of the most exciting science
topics is the detection and observation of gamma-ray bursts (GRBs). In this
paper we present the work done so far by the GRB LAT science group in studying
the performance of the LAT detector to observe GRBs. We report on the
simulation framework developed by the group as well as on the science tools
dedicated to GRBs data analysis. We present the LAT sensitivity to GRBs
obtained with such simulations, and, finally, the general scheme of GRBs
detection that will be adopted on orbit.Comment: 6 pages, 3 figures. Proceedings for the 16th Annual October
Astrophysics Conference in Maryland: Gamma Ray Bursts in the Swift Er
- …