GRB Probes of the High-z Universe with EXIST
Abstract
The Energetic X-ray Imaging Survey Telescope (EXIST) mission concept was selected for further study under the Astrophysics Strategic Mission Concept Study (ASMCS) program. The mission design is optimized for study of high-z GRBs as probes of the early Universe. With a 4.5 m2 imaging 5-600 keV (CZT) detector imaging a 90°×70° (>10% coding fraction) field of view with 2' resolution and <20'' (90% conf.) positions for >5σ sources, EXIST will perform rapid (<200 sec) slews onto GRBs and obtain prompt images and spectra with a co-aligned soft X-ray telescope 0.1-10 keV) and with a 1.1 m optical-IR telescope (IRT) simultaneously in 4 bands (0.3-0.52 μm, 0.52-0.9 μm, 0.9-1.38 μm, and 1.38-2.3 μm) for prompt identification (by dropouts or variability) of the GRB within a 3.75×4.25' FoV. An autonomous spacecraft re-point (<2') will then (at ~300 sec after GRB trigger) put the GRB on a 0.2×10'' slit for either R = 3000 (for AB <21) or R = 30 (for AB ~21-25) prompt spectra over the 0.3-0.9 μm and 0.9-2.3 μm bands. This will provide onboard redshifts within ~500-2000 sec for most GRBs, reaching z ~20 (for Lyman-α breaks) if such GRBs exist, and spectra for studies of the host galaxy and local re-ionization bubble as well as intervening cosmic structure. With ~600 GRBs/yr expected, EXIST will open a new era in studies of the early Universe as well as carry out a rich program of AGN and transient-source science. An overview of the GRB science objectives and a brief discussion of the overall mission design and operations is given, and example high-z GRB spectra are shown. EXIST is being proposed to the Astro2010 Decadal Survey as a Medium Class mission that could be launched as early as 2017.
- Publication:
-
Gamma-ray Burst: Sixth Huntsville Symposium
- Pub Date:
- May 2009
- DOI:
- 10.1063/1.3155875
- arXiv:
- arXiv:0904.2210
- Bibcode:
- 2009AIPC.1133...18G
- Keywords:
-
- 98.70.Rz;
- 95.55.-n;
- 98.62.Js;
- gamma-ray sources;
- gamma-ray bursts;
- Astronomical and space-research instrumentation;
- Galactic nuclei circumnuclear matter and bulges;
- Astrophysics - Cosmology and Extragalactic Astrophysics;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 7 pages, 5 figures, 1 table