ALMA as a Probe of Cold Dark Matter Subhalos

The cold dark matter scenario predicts the existence of large numbers of dark matter subhalos in the dwarf-galaxy mass range, and high-resolution ALMA observations may be able to detect these objects against the individual images of lensed sub-mm galaxies. Here, we model the simulated visibilities of strong lensing systems to estimate the minimum subhalo mass that may produce image distortions that are observable with ALMA using the 16 km baselines. We find that subhalos with virial masses as low as similar to 10(7) M-circle dot should be readily detectable using this technique.