Polarization modulation from Lense-Thirring precession in X-ray binaries

Understand

It has long been recognised that quasi-periodic oscillations (QPOs) in the X-ray light curves of accreting black hole and neutron star binaries have the potential to be powerful diagnostics of strong field gravity.

• However, this potential cannot be fulfilled without a working theoretical model, which has remained elusive.
• Perhaps the most promising model associates the QPO with Lense-Thirring precession of the inner accretion flow, with the changes in viewing angle and Doppler boosting modulating the flux over the course of a precession cycle.
• Here, we consider the polarization signature of a precessing inner accretion flow.