University of Pennsylvania
Department of Physics and Astronomy
High Energy Physics Seminar

Abstract

The Gamma-Ray Large Area Space Telescope (GLAST), scheduled to be launched in 2007, is the next generation satellite for high-energy gamma-ray astronomy. GLAST consists of two instruments, the Large Area Telescope (LAT) and the GLAST Burst Monitor (GBM). This talk will focus primarily on the LAT, which is a pair conversion telescope built with a plastic anti-coincidence shield, a segmented CsI electromagnetic calorimeter, and silicon strip tracker. Onboard, the LAT uses hardware triggers that are efficient for determining gamma-ray candidate events, along with subsequent software filters that reduce the data volume by an additional factor of ~10 to meet the downlink requirements. Incorporated in the onboard software are algorithms for identifying transients such as Gamma Ray Bursts and flaring states of Active Galactic Nuclei. GLAST will open a new window on a numberof interesting high energy phenomena, among them the study of gamma-ray bursts and active galactic nuclei, searches for hypothetical new phenomena such as supersymmetric dark matter annihilations, Lorentz invariance violation, and exotic relics from the Big Bang. This talk will present an overview of the LAT instrument design and construction, a description of the hardware and software trigger algorithms and their impact on event selection and onboard science, and some discussion on the expected science topics to look for in the first few years of GLAST data.