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arXiv · 0711.3754

The trigger function of the space borne gamma-ray burst telescope ECLAIRs

S. Schanne·B. Cordier·D. Gotz·A. Gros·P. Kestener·H. Le Provost·B. L'Huillier·M. Mur
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Abstract

Gamma-ray bursts (GRB) sign energetic explosions in the Universe, occurring at cosmological distances. Multi-wavelength observations of GRB allow to study their properties and to use them as cosmological tools. In 2012 the space borne gamma-ray telescope ECLAIRs is expected to provide accurate GRB localizations on the sky in near real-time, necessary for ground-based follow-up observations. Led by CEA Saclay, France, the project is currently in its technical design phase. ECLAIRs is optimized to detect highly red-shifted GRB thanks to a 4 keV low energy threshold. A coded mask telescope with a 1024 cm^2 detection plane of 80x80 CdTe pixels permanently observes a 2 sr sky field. The on-board trigger detects GRB using count-rate increase monitors on multiple time-scales and cyclic images. It computes sky images in the 4-50 keV energy range by de-convolving detector plane images with the mask pattern and localizes newly detected sources with <10 arcmin accuracy. While individual GRB photons are available hours later, GRB alerts are transmitted over a VHF network within seconds to ground, in particular to robotic follow-up telescopes, which refine GRB localizations to the level needed by large spectroscopic telescopes. This paper describes the ECLAIRs concept, with emphasis on the GRB triggering scheme.

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S. Schanne, B. Cordier, D. Gotz, A. Gros, P. Kestener, H. Le Provost, B. L'Huillier, M. Mur. 2007-11-23. The trigger function of the space borne gamma-ray burst telescope ECLAIRs. https://arxiv.org/abs/0711.3754

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