Low-frequency quasi-periodic oscillations and shocks in accretion on to black hole

Chandra B. Singh, Yunnan University
Santanu Mondal, Indian Institute of Astrophysics
David Garofalo, Kennesaw State University


Low-frequency quasi-periodic oscillations (LFQPOs) have been routinely observed in black hole X-ray binaries (BHXRBs). These LFQPOs can be explained by axisymmetric shock oscillation in accretion flow around a rotating black hole. We address the physical origin of Type-C LFQPOs in BHXRBs observed by the Rossi X-ray Timing Explorer satellite considering a minimum number of free parameters, namely, specific energy and specific angular momentum of the infalling matter for a given set of BH mass and spin parameter. We apply the solution for a large number of BH candidates to further strengthen the scenario of an anticorrelation between the QPO frequency and the location of the shock. Our study also confirms that Compton cooling can be sufficient to explain the observed QPOs.