Using the Active Collimator and Shield Assembly of an EXIST-Type Mission as a Gamma-Ray Burst Spectrometer
arXiv:astro-ph/0606065 · doi:10.1051/0004-6361:20053674
Abstract
The Energetic X-ray Imaging Survey Telescope (EXIST) is a mission design concept that uses coded masks seen by Cadmium Zinc Telluride (CZT) detectors to register hard X-rays in the energy region from 10 keV to 600 keV. A partially active or fully active anti-coincidence shield/collimator with a total area of between 15 and 35 square meters will be used to define the field of view of the CZT detectors and to suppress the background of cosmic-ray-induced events. In this paper, we describe the use of a sodium activated cesium iodide shield/collimator to detect gamma-ray bursts (GRBs) and to measure their energy spectra in the energy range from 100 keV up to 10 MeV. We use the code GEANT4 to simulate the interactions of photons and cosmic rays with the spacecraft and instrument and the code DETECT2000 to simulate the optical properties of the scintillation detectors. The shield collimator achieves a nu-F-nu sensitivity of 3 x 10^(-9) erg cm^(-2) s^(-1) and 2 x 10^(-8) erg cm^(-2) s^(-1) at 100 keV and 600 keV, respectively. The sensitivity is well matched to that of the coded mask telescope. The broad energy coverage of an EXIST-type mission with active shields will constrain the peak of the spectral energy distribution (SED) for a large number of GRBs. The measurement of the SED peak may be key for determining photometric GRB redshifts and for using GRBs as cosmological probes.
20 pages, 10 Figures, Accepted May 19, 2006 A&A
References in corpus (22)
- Gamma-Ray Bursts as the Death Throes of Massive Binary Stars
- Intrinsic spectra and energetics of BeppoSAX Gamma-Ray Bursts with known redshifts
- Spectroscopic Discovery of the Supernova 2003dh Associated with GRB 030329
- Are Gamma-Ray Bursts in Star Forming Regions?
- Theories of Gamma-Ray Bursts
- GRB Formation Rates inferred from the Spectral Peak Energy - Luminosity Relation
- The collimation--corrected GRB energies correlate with the peak energy of their spectrum
- Connection Between Energy-dependent Lags And Peak Luminosity In Gamma-ray Bursts
- A Possible Cepheid-Like Luminosity Estimator for the Long Gamma-Ray Bursts
- The Cooling Behavior of Thermal Pulses in Gamma-Ray Bursts
- Implications of Lag-Luminosity Relationship for Unified GRB Paradigms
- Cosmological Aspects of Gamma-Ray Bursts: Luminosity Evolution and an Estimate of the Star Formation Rate at High Redshifts
- Luminosity Function of Gamma-Ray Bursts Derived Without Benefit of Redshifts
- Discovery and identification of the very high redshift afterglow of GRB 050904
- Early Afterglow Emission from a Reverse Shock as a Diagnostic Tool for GRB Outflows
- BATSE Observations of Gamma-Ray Burst Spectra. IV. Time-Resolved High-Energy Spectroscopy
- Highlights of the HETE-2 Mission
- Scientific Highlights of the HETE-2 Mission
- On The Spectral Energy Dependence of Gamma-Ray Burst Variability
- In-flight performances of the BeppoSAX Gamma-Ray Burst Monitor
- A Mass Model for Estimating the Gamma Ray Background of the Burst and Transient Source Experiment
- EXIST: All-Sky Hard X-ray Imaging and Spectral-Temporal Survey for Black Holes