A Search for Pulsed TeV Gamma Ray Emission from the Crab Pulsar
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چکیده
We present the results of a search for pulsed TeV emission from the Crab pulsar using the Whipple Observatory’s 10 m gamma-ray telescope. The direction of the Crab pulsar was observed for a total of 73.4 hours between 1994 November and 1997 March. Spectral analysis techniques were applied to search for the presence of a gamma-ray signal from the Crab pulsar over the energy band 250 GeV to 4 TeV. At these energies we do not see any evidence of the 33 ms pulsations present at lower energies from the Crab pulsar. The 99.9% confidence level upper limit for pulsed emission above 250 GeV is derived to be 4.8×10−12cm−2s−1 or <3% of the steady flux from the Crab Nebula. These results imply a sharp cut-off of the power-law spectrum seen by the EGRET instrument on the Compton Gamma-Ray Observatory. If the cut-off is exponential, it must begin at 60 GeV or lower to accommodate these upper limits.
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تاریخ انتشار 1999