Measuring Black Hole Spin using X-ray Reflection Spectroscopy

Understand

I review the current status of X-ray reflection (a.k.a.

• broad iron line) based black hole spin measurements.
• This is a powerful technique that allows us to measure robust black hole spins across the mass range, from the stellar-mass black holes in X-ray binaries to the supermassive black holes in active galactic nuclei.
• After describing the basic assumptions of this approach, I lay out the detailed methodology focusing on "best practices" that have been found necessary to obtain robust results.