Quasiperiodic oscillation around charged black holes in Einstein–Maxwell-scalar theory

Abstract

AbstractIn the present paper, first, we study the event horizon properties of charged black holes (BHs) in Einstein Maxwell-scalar (EMS) gravity. Then, we investigate the circular motion of test particles’ around the BH in the EMS gravity. We also analyze the effects of the EMS parameters on the position of innermost circular orbits (ISCOs), energy, and angular momentum of the test particles corresponding to circular orbits. We provide detailed studies of the efficiency of energy release from EMS BHs based on the Hartle–Thorne model and fundamental frequencies of oscillations of particles along their circular stable orbits. Moreover, we have explored possible values of upper and lower frequencies of twin-peak quasiperiodic oscillations (QPOs) around the BHs. Finally, we obtain relationships between the BH charge and the EMS parameters using observational data from the QPOs detected in the microquasars: GRS 1905+105, GRO J 1655-40, H 1745+322, and XTE 1550-564.