Is gravitational lensing a local phenomenon caused by Pop - III objects?

Abstract

Gravitational lensing action by the massive black hole remnants of Pop II objects located within the halo of the Galaxy is explored as an explanation for observational features including the separation and intensity ratio of the images of multiply-imaged quasars. The present model leads to the two-image configuration by a point mass deflector without any fine-tuning of the lens parameters, and both the mass and the distance are more severely constrained than the range of parameters used in the usual picture of lensing by extended deflectors. Comparison is made with observations, and it is found that only some of the systems can be attributed to lensing by Pop III. The absence of lensing candidates can be explained in some of the cases.