Graduate Student Seminar with Andrew West On the Origin of Quasi-Periodic Oscillations in Black Hole X-Ray Binaries

Quasi-Periodic Oscillations (QPOs) of the X-Ray flux from stellar mass black hole X-Ray binaries have been observed for decades and many possible mechanisms have been proposed to explain their origin, including the precession of the innermost regions of the accretion flow. Recently, the H-AMR collaboration led by M. Liska have shown that a highly misaligned, thin disk undergoes cyclical tearing events wherein the inner disk separates from the outer disk and precesses in a quasi-Bardeen-Petterson configuration. G. Musoke showed that the signatures of both a high frequency and low frequency QPO are present in the mass accretion rate (Musoke et al, 2022) during a cycle of tearing. I present here the results of post-processing this General Relativistic Magneto-Hydrodynamical dataset with the fully general relativistic raytracing code xTrack. The results show that these QPO signatures, for the first time, result in spectral QPOs in the thermal emission from the disk existing in both 2:1 and 3:2 harmonics. While the main peak of these QPOs corresponds to the radial epicyclic frequency of the tearing radius, I show that the signal itself represents a global mode emanating from both within the inner disk and throughout the outer disk.