Presentation #231.07 in the session “Binary Stellar Systems II”.
Quasi-periodic oscillations (QPOs) are features that appear as peaks in the power spectrum of X-ray binaries. The bicoherence is a measure of the strength of phase coupling among triplets of frequencies, and can be used to break degeneracies between models that produce very similar power spectra. The black hole X-ray binary GRS 1915+105 uniquely shows all three known bicoherence patterns of type C QPOs, compared to other black holes that only exhibit two of the three patterns. We will discuss the different types of phase coupling seen between the QPO and noise components, and how they relate to the radio properties of the source. We also present a qualitative interpretation of the results in the context of the Lense-Thirring precession model.