Ring Position Angles and Spin in M87* and Sgr A*
This study analyzes position angles of brightness asymmetries in Event Horizon Telescope images of M87* and Sgr A*. By comparing EHT data to GRMHD simulations, researchers constrain black hole spin and orientation. Findings suggest larger spins are favored, while M87's asymmetry aligns with its jet axis, indicating a small disk tilt. The analysis provides constraints on prograde/retrograde motion for M87 and galactic center spin for Sgr A.