X-Ray Quasi-periodic Oscillations in the Lense-Thirring Precession Model. I. Variability of Relativistic Continuum

摘要: We develop a Monte Carlo code to compute the Compton-scattered X-ray flux arising from hot inner flow that undergoes Lense–Thirring precession. The intercepts seed photons an outer truncated thin disk. A fraction of Comptonized will illuminate disk, and reflected/reprocessed contribute observed spectrum. total spectrum, including disk thermal emission, Comptonization, reflection, is modeled within framework general relativity, taking light bending gravitational redshift into account. simulations are performed in context precession model for low-frequency quasi-periodic oscillations, so assumed precess, leading periodic modulation emitted radiation. In this work, we concentrate on energy-dependent variability and, particular, evolution during spectral transition hard soft state, which implemented by decrease truncation radius toward innermost stable circular orbit. where Comptonizing geometrically thick, Comptonization weakly variable with fractional amplitude ≤10%; cooled down thus becomes thin, highly variable, increasing photon energy. reflection increases energy, emission low spin counterintuitively more than one high spin.