Simulating Subhalos at High Redshift: Merger Rates, Counts, and Types

Understand

Galaxies are believed to be in one-to-one correspondence with simulated dark matter subhalos.

• We use high-resolution N-body simulations of cosmological volumes to calculate the statistical properties of subhalo (galaxy) major mergers at high redshift (z=0.6-5).
• We measure the evolution of the galaxy merger rate, finding that it is much shallower than the merger rate of dark matter host halos at z>2.5, but roughly parallels that of halos at z<1.6.
• We also track the detailed merger histories of individual galaxies and measure the likelihood of multiple mergers per halo or subhalo.