Detection of very high energy gamma rays from the Crab source

The Thermistocle experiment, which consists of an array of 18 Cherenkov telescopes located on the French Pyrenees, has successfully observed the emission of multi‐TeV gamma rays from the CRAB source, with a significance corresponding to 6.5 standard deviations. The source is resolved with an accuracy of 2.5 mr (≂8 arc min.) per shower. The observation of the signal relies uniquely on the high angular resolution in determining the direction of the individual showers. The source is localized with the precision of the order of 0.5 mr (≂2 arc min.) in an energy range so far unexplored. The energy of the gammas is estimated by measuring the amplitude of the Cherenkov signal detected by each of the 18 telescopes. The energy spectrum of the CRAB gamma source is determined in the range from 3 to 15 TeV. The results are compatible with a power extrapolation of the data available at lower energies (<1 TeV).