Constraining the nature of galaxy haloes with gravitational mesolensing of QSOs by halo substructure objects

TL;DR

This paper explores how gravitational mesolensing of quasars by halo substructures like globular clusters and dark matter clumps can reveal the nature of galaxy haloes, using optical interferometry for observational constraints.

Contribution

It demonstrates that optical interferometry can effectively constrain the mass and number of halo substructure objects, providing a direct test of galaxy halo composition.

Findings

Evidence of gravitational lensing by globular clusters in galaxy haloes

Optical interferometry constrains masses of halo substructures

Supports the presence of dark matter clumps in galaxy haloes

Abstract

Gravitational lensing of background compact objects like active galactic nuclei and quasars, by extended intermediate mass lenses such as globular clusters and and dark matter clumps with masses 10^5 - 10^8 M_sun, is considered. It is shown that observational study of the galaxy-quasar's associations is a powerful direct observational test of the nature of massive galaxy haloes. Optical interferometric observations with VLTI and Keck instruments are able to constrain masses and number of substructure halo objects. Evidence of gravitational lensing by globular clusters in haloes of spiral and elliptical galaxies is presented.