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تسجيل مستخدم جديدStudy of Mrk 501 above 60 GeV with CELESTE
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E. Brion
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The CELESTE atmospheric Cherenkov detector, running until June 2004 at the Themis solar facility, has taken data on compact sources such as pulsars and blazars. We will take stock of the experiment, in particular regarding the latest improvements of the detector simulation and data analysis. These changes provide us with a new analysis of old data with smaller uncertainties. We present here the evidence for a weak signal from Mrk 501 in 2000-2001.
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The new analysis variable xi, shown to be powerful on the data taken with the final configuration of CELESTE, has been applied to data taken with previous detector configurations. First, the analysis is validated on Crab observations, and then the cu
ts for the blazar Mrk 501 are optimized using Mrk 421 data since the sources have similar declinations. Data from Mrk 501 was recorded in 2000 and 2001. The old analysis gave a 2.5 sigma excess. We obtain an excess of 2.9 sigma during this time and of 4.9 sigma during May and June 2000 that we interpret as a gamma-ray signal from Mrk 501, for which we calculate a flux of (6.9 +/- 2.2) * 10^{-7} photons m^{-2} s^{-1}. An upper limit from the other data with no signal is determined.
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