GM070

Gravitational lensing by low-mass dark matter haloes

Abstract

We request 13 hrs Global VLBI observations at 1.7 GHz of the gravitational lens MG
J0751+2716. The aim of these observations is to image the extended gravitational arcs of the
radio-loud jets at mas resolution. These data will be used to find evidence of low mass
substructure (~10^8 solar mass dark matter haloes) hosted in the massive ~10^12 solar
mass lensing galaxy. Low mass substructure would be detected through the small
perturbations that they produce on the extended gravitational arcs. The excellent resolution
and sensitivity of the proposed observations could image the small radius (~5 mas) Einstein
rings that substructure is expected to produce. The detection of low mass substructure in the
lensing galaxy would strongly constrain cold dark matter models of galaxy formation and give
the most stringent constraints to the low-end of the substructure mass function.

Investigators

Name	Institution
Toney Minter *	Green Bank Observatory
John McKean	Netherlands Institute for Radio Astronomy; Kapteyn Astronomical Institute
Matthew Auger	California at Davis, University of; Cambridge, University of
Chris Fassnacht	California at Davis, University of
Neal Jackson	Manchester, University of
Leon Koopmans	Kapteyn Astronomical Institute
David Lagattuta	California at Davis, University of
Simona Vegetti	Massachusetts Institute of Technology

* indicates the PI