Lens Mapping of Dark Matter Substructure with VSOP-2

TL;DR

This paper proposes using high-resolution radio observations with VSOP-2 to directly detect dark matter substructures in galaxy halos through gravitational lensing effects on multiply imaged QSOs.

Contribution

It introduces a novel observational method to identify dark matter subhalos by mapping their gravitational lensing signatures using VSOP-2.

Findings

Potential to detect 5-10% of galaxy halo mass in substructures

Method can identify subhalos with masses <= 10^8 M_sun

Enhances understanding of dark matter distribution in galaxies

Abstract

Hierarchical clustering models of cold dark matter (CDM) predict that about 5% - 10% of a galaxy-sized halo with mass ~ 10^12 solar masses (M_sun) resides in substructures (CDM subhalos) with masses <= 10^8 M_sun. To directly identify such substructures, we propose to observe radio continuum emission from multiply imaged QSOs using VSOP-2 with a high angular resolution.