Dark Matter Substructure: A lensing perspective

Theories of dark matter have been successful at modeling galaxies and providing explanation for many astrophysical phenomena. Despite this success, little is known about the properties of dark matter. A large model space of viable dark matter theories exists, each providing different descriptions of dark matter and it's effect on galactic physics. Currently, two of the leading theories are cold dark matter (CDM) and warm dark matter (WDM). These two theories make different predictions on the substructure expected within dark matter halos. Gravitational lensing provides a promising method of probing the substructure of dark matter halos and thus testing the predictions of CDM and WDM. However, simulating the substructure within the lensing galaxy's aperture has proven difficult. Predictions from N-body and semi-analytic models for the number density of subhalos within this region span nearly an order of magnitude. Additionally, recent work has drawn attention to the effects of artificial disruption, an effect which may cause the spurious suppression of the subhalo mass function in N-body simulations up to a factor of 2 in the innermost region. Currently, we are investigating using galacticus, a semi-analytic galaxy formation toolkit tuned to state-of-the-art idealized simulations. We present a large suite of galacticus realizations, spanning nearly two orders of magnitude in host halo mass and study the population level statistics of subhalos.