Measurement method of black hole spin and its application in jet

Abstract

Spin is an important property of black holes. The formation of jet and black hole is related to spin. At present, there are two commonly used spin measurement methods, the X-ray reflection method, and the continuum-fitting method. By analyzing the distribution of black hole spin in black hole binary system measured by these two methods, we find that in high-mass X-ray binaries, black holes have high spin, this is because the companion stars have a large mass and short lifetime, the black holes don’t have enough time to accelerate the spin by accretion so must be bored with high spin. However, in low-mass X-ray binaries, the spin will be widely distributed because they have enough time to increase spin by accreting gas. And according to the existing data, we can also get the relationship between spin and jet. However, both methods are affected by the complex physics of the accretion disk, in the future, gravitational waves will become another effective tool to measure the spin of black holes.