Catching GRBS from the Ground

arXiv:1102.2112 [pdf, ps, other]

Catching GRBs with atmospheric Cherenkov telescopes

Rudy C. Gilmore, Joel R. Primack, Aurelien Bouvier, A. Nepomuk Otte

Comments: 4 pages, 3 figures, to appear in the Proceedings of "Gamma Ray Bursts 2010", held Nov. 1-4, 2010 in Annapolis, MD

Subjects: High Energy Astrophysical Phenomena (astro-ph.HE)

Fermi has shown GRBs to be a source of >10 GeV photons. We present an estimate of the detection rate of GRBs with a next generation Cherenkov telescope. Our predictions are based on the observed properties of GRBs detected by Fermi, combined with the spectral properties and redshift determinations for the bursts population by instruments operating at lower energies. While detection of VHE emission from GRBs has eluded ground-based instruments thus far, our results suggest that ground-based detection may be within reach of the proposed Cherenkov Telescope Array (CTA), albeit with a low rate, 0.25 - 0.5/yr. Such a detection would help constrain the emission mechanism of gamma-ray emission from GRBs. Photons at these energies from distant GRBs are affected by the UV-optical background light, and a ground-based detection could also provide a valuable probe of the Extragalactic Background Light (EBL) in place at high redshift.