Role of Shocked Accretion Flows in Regulating the Quasi-periodic Oscillation of Galactic Black Hole Candidates

Abstract

Using a generalized nonspherical, multitransonic accretion flow model, we analytically calculate the normalized quasi-periodic oscillation (QPO) frequency qpo of Galactic black hole candidates in terms of dynamical flow variables and self-consistently study the dependence of qpo on such variables. Our results are in fairly close agreement with the observed QPO frequencies of GRS 1915+105. We find that qpo is quite sensitive to various parameters describing the black hole accretion flow containing dissipative and nondissipative shock waves. Thus, the QPO phenomena is, indeed, regulated by shocked black hole accretion, and, for the first time, we establish a definitive connection between the QPO frequency and the properties of advective black hole accretion flows. This information may provide an explanation for some of the important observations of Galactic microquasars.