Orbital Periodicities in the Hard Emission from X-ray Transient - Black Hole Candidates Between Outbursts

M. I. Kudryavtsev, S. I. Svertilov, V. V. Bogomolov

During long-term observations of the Galactic Centre region in hard X-rays (10-300 keV) in space experiments made on board Prognoz-9 satellite and "Mir" orbital station (GRIF exper…