Gravitational lensing by the supermassive black hole in the center of the Andromeda galaxy(*)

摘要

We study the gravitational lensing effects in the weak deflection regime by the supermassive black hole in the center of the galaxy M31 on background stai populations belonging to the galactic components of M31: the bulge, the disk, the triple nucleus formed by P1+P2 and by the inner cluster P3, In particular, we calculate the number of expected lensed sources at a given time whose secondary image is blighter than a specific threshold magnitude.