Reproducing the Kinematics of Damped Lyman-alpha Systems

Understand

We examine the kinematic structure of Damped Lyman-alpha Systems (DLAs) in a series of cosmological hydrodynamic simulations using the AREPO code.

• We are able to match the distribution of velocity widths of associated low ionisation metal absorbers substantially better than earlier work.
• Our simulations produce a population of DLAs dominated by halos with virial velocities around 70 km/s, consistent with a picture of relatively small, faint objects.
• In addition, we reproduce the observed correlation between velocity width and metallicity and the equivalent width distribution of SiII.