2 research outputs found
On the sensitivity of the HAWC observatory to gamma-ray bursts
We present the sensitivity of HAWC to Gamma Ray Bursts (GRBs). HAWC is a very
high-energy gamma-ray observatory currently under construction in Mexico at an
altitude of 4100 m. It will observe atmospheric air showers via the water
Cherenkov method. HAWC will consist of 300 large water tanks instrumented with
4 photomultipliers each. HAWC has two data acquisition (DAQ) systems. The main
DAQ system reads out coincident signals in the tanks and reconstructs the
direction and energy of individual atmospheric showers. The scaler DAQ counts
the hits in each photomultiplier tube (PMT) in the detector and searches for a
statistical excess over the noise of all PMTs. We show that HAWC has a
realistic opportunity to observe the high-energy power law components of GRBs
that extend at least up to 30 GeV, as it has been observed by Fermi LAT. The
two DAQ systems have an energy threshold that is low enough to observe events
similar to GRB 090510 and GRB 090902b with the characteristics observed by
Fermi LAT. HAWC will provide information about the high-energy spectra of GRBs
which in turn could help to understanding about e-pair attenuation in GRB jets,
extragalactic background light absorption, as well as establishing the highest
energy to which GRBs accelerate particles
Performance of the MAGIC stereo system obtained with Crab Nebula data
MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in
the Canary island of La Palma. Since autumn 2009 both telescopes have been
working together in stereoscopic mode, providing a significant improvement with
respect to the previous single-telescope observations. We use observations of
the Crab Nebula taken at low zenith angles to assess the performance of the
MAGIC stereo system. The trigger threshold of the MAGIC telescopes is 50-60
GeV. Advanced stereo analysis techniques allow MAGIC to achieve a sensitivity
as good as (0.76 +/- 0.03)% of the Crab Nebula flux in 50 h of observations
above 290 GeV. The angular resolution at those energies is better than ~0.07
degree. We also perform a detailed study of possible systematic effects which
may influence the analysis of the data taken with the MAGIC telescopes.Comment: 15 pages, 19 figures, 4 tables, added run-by-run systematics study,
and the study of angular resolution as the function of the distance to the
camera centre, accepted for publication in Astroparticle Physic