CHARACTERISTICS OF THE PERIODIC HARD X-RAY SOURCES DISCOVERED DURING THE PROGNOZ-9 EXPERIMENT - THE RESULTS OF A FURTHER ANALYSIS

During the Prognoz-9 experiment, we searched for periodic sources in t he hard X-ray range (10-200 keV), No periodicities were detected durin g the observations of regions offset from the Galactic plane and the G alactic-''anticenter'' region, A further analysis of the data refined the list of observed periodic sources in the Galactic-center region wi th periods of hours and days. In addition to the previously detected p eriodicities-152 h (Nova Ophiuchi 1977), 98 h, 82 h (4U 1700-37), 69 h , 62 h, 13.3 h, 9.36 h, 8.15 h (Cen X-4), 4.35 h (4U 1755-33), and 3.4 5 h-we found new periodic sources: 8.04, 4.38, and 1.47 h. The mean ph ase profiles (light curves) in various energy bands were constructed f or all the observed periodicities. The mean phase profiles for most of the observed periodic sources differ in shape: from harmonic and pure ly ''eclipsing'' profiles, Evidence was obtained for the presence of p eculiar phase features in some of the light curves.