Inference of the Cold Dark Matter substructure mass function at z=0.2 using strong gravitational lenses

Understand

We present the results of a search for galaxy substructures in a sample of 11 gravitational lens galaxies from the Sloan Lens ACS Survey.

• We find no significant detection of mass clumps, except for a luminous satellite in the system SDSS J0956+5110.
• We use these non-detections, in combination with a previous detection in the system SDSS J0946+1006, to derive constraints on the substructure mass function in massive early-type host galaxies with an average redshift z ~ 0.2 and an average velocity dispersion of 270 km/s.
• We perform a Bayesian inference on the substructure mass function, within a median region of about 32 kpc squared around the Einstein radius (~4.2 kpc).