Ultrahigh-Energy Pulsed Emission from Hercules X-1 with Anomalous Air-Shower Muon Production

Abstract

A search for bursts of air-shower events from Hercules X-l at energies above 50 TeV during the calendar period 2 April 1986 to 5 July 1987 yielded two significant bursts, both occurring on UT 24 July 1986. The events during these bursts were pulsed with a period of 1.235 68 s, significantly different from estimates of the contemporaneous x-ray period. The probability that this represents random statistical fluctuations of the background is estimated to be 2xl0~5. The muon content of the burst events is anomalous when compared with expectations from 7-ray showers.PACS numbers: 97.80. Jp, 95.85.Qx, 97.60.Gb, 98.60.Df

Cosmic-ray deficit from the directions of the Moon and the Sun detected with the Tibet air-shower array

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