The spin measurement of black holes in active galactic nucleus

Abstract

Spin as one of the two parameters describing black holes. Measuring the spin of black holes is very important in black holes research. In this paper, we introduce the method to measure the spin of AGNs which is the X-ray reflection method, including both specific content and precautions. Based on this method, we select 25 aim objects and give the spin number. The spins mainly focus on 0.5~1. The selection effect is shortly discussed in this paper. Gravitational waves may be next major technology to measure the spin of AGNs. Gravitational waves method is also briefly introduced in this paper.