Neal Dalal (Univ. Illinois at Urbana-Champaign) "Detecting Dark Matter Substructure Using ALMA"

Abstract: 
Dark matter halos surrounding galaxies are expected to contain copious substructure, in the form of gravitationally bound subhalos.  Local Group observations suggest that our Galaxy has a deficit of substructure (the Missing Satellites Problem), possibly indicating new physics in the dark sector.  I will describe how gravitational lensing may be used to measure the amount of dark substructure that exists in typical galaxy halos.  In particular, I will explain how observations by the newly commissioned ALMA observatory of dusty galaxies from CMB surveys can probe halo substructure.  I will show first results from our ALMA Cycle 2 observations, and argue that ALMA should be able to answer the Missing Satellites Problem in upcoming years.