Balloon Observations of X-Rays from Celestial Sources

Abstract

In the last three years, four successful balloon flights were made from Hyderabad, India, to investigate the different features of the emission of X-rays from celestial sources such as Sco X-1, Cyg X-1 and Her X-1. These observations were carried out by Nal(T1) scintil1ation telescopes mounted on oriented platforms and programmed to track the sources in azimuth and elevation. The data obtained from these flights are used to study the intensity and spectra of these sources. For Cyg X-1, the fluctuati.ons in the intensity and the corresponding spectra, with time scales of a few minutes are reported. Her X-1 has been observed in two separate flights at the time of maximum and minimum of its intensity states corresponding to the 35-day cycle.