55 research outputs found
Catching GRBs with atmospheric Cherenkov telescopes
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.Comment: 4 pages, 3 figures, to appear in the Proceedings of "Gamma Ray Bursts
2010", held Nov. 1-4, 2010 in Annapolis, M
First Detection of the Crab Pulsar above 100 GeV
We present the detection of pulsed gamma-ray emission from the Crab pulsar
above 100 GeV with the VERITAS array of atmospheric Cherenkov telescopes.
Gamma-ray emission at theses energies was not expected in pulsar models. The
detection of pulsed emission above 100 GeV and the absence of an exponential
cutoff makes it unlikely that curvature radiation is the primary production
mechanism of gamma rays at these energies.Comment: 5 pages, proceedings of the TAUP 2011 conference in Munich, German
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