Routines to get merger rates from the paper:
Mergers and Bulge Formation in Lambda-CDM: Which Mergers Matter?
Hopkins, P. F., Bundy, K., Croton, D., Hernquist, L., Keres, D., Khochfar, S.,
Stewart, K., Wetzel, A., & Younger, J.D., 2009, ApJ, arXiv:0906.5357
An IDL script to return the galaxy-galaxy (or halo-halo) merger rate, as a function of galaxy mass (stellar or baryonic) or halo mass, redshift, galaxy gas fractions, and other properties. It can return either the volumetric merger rate (mergers per unit volume per unit time), or merger rate per galaxy; optionally, this can be converted into a merger fraction as well, for different observational criteria. The method is based on the semi-empirical (halo-occupation based) model in the paper (although the version used in this script is somewhat condensed, to make it quick and self-contained). Inputs such as the cosmological parameters and observed galaxy stellar mass functions used to normalize the halo occupation model can be varied as well.
The beginning lines of the code explain its use and range of applicability.
Please, email me if you have any questions about using these routines and/or data, or would like to use the script or results in a different format. I’m happy to help.