Two Bursts of Ultra-High Energy Gamma Rays Detected by the Baksan Air Shower Array

Abstract

During a Cygnus X-3 campaign many years ago the Carpet air shower array of the Baksan Neutrino Observatory had recorded two bursts from two different sources: from the Crab Nebula on February 23, 1989 and from Cygnus X-3 on October 14–16, 1985. The characteristics of the bursts were quite different, as well as types of the source objects. The first of these bursts was discussed in some detail after registration of regular flares of gamma rays with energies of several hundred MeV by the satellite gamma-ray telescopes FermiLAT and AGILE. The second burst was not discussed in recent time, and in this paper attention is attracted to it in connection with the new results of the Tibet ASγ collaboration.