Abstract
Blurred reflection features are regularly detected in the X-ray spectra of accreting black holes. They result from the coronal photons' illumination of cold accretion disk material. X-ray reflection spectroscopy refers to the study of these blurred reflection features. In the case of high-quality data and a correct astrophysical model, X-ray reflection spectroscopy can be a powerful tool for studying the morphology of accreting matter, measuring the spin of black holes, and possibly testing general relativity in the strong field limit. Significant progress has been made in the past decade toward perfecting relativistic reflection models. Yet, these models rely on a number of simplifications that deviate from reality and can result in systematic bias in final parameter estimates of accreting black holes. In this presentation, I will discuss systematic bias in measuring black hole spin due to the structure of the accretion disk and the returning radiation.
Biography
Dr. Shafqat Riaz is a Postdoctoral Fellow at Fudan University. He received his PhD from Fudan University in 2021. He works on X-ray astrophysics around black holes, and focuses on developing relativistic reflection models, studying systematic bias in the reflection models, analyzing X-ray data from accreting black holes, and testing GR in the strong field limit using X-ray data.
Anyone interested is welcome to attend.