Rapid Fluctuations in the High-Energy X-Ray Flux from a Source in Crux

Abstract

On 1970 October 15-16 we carried out balloon X-ray observations from Australia (energies above 15 keV). We detected a rapidly varying flux from a source at 1" = + 0?5, b" = -2?2 + 2?7 (OX 301 - 2). Several flares with rise and decay time of a few minutes were recorded. A flux change of about a factor of 5 was recorded in 2.5 minutes. The highest flux observed in the energy range from 15 to 32 keV was 10 keV . This is at least a factor of 35 higher than the average flux from this region of the sky measured on 1969 March 20 by Lewin, McClintock, and Smith. The lowest flux measured from OX 301-2 during the 1970 October observation is 2 keV . In the same energy range we also observed a source at t" = 303?8 + 0?8, b" = 10.2 + 20.5 (OX 304-I). The flux from this source was about 1 keV .