Sokasian, A.Abel, T.Hernquist, L. E.2019-09-202001Sokasian, A., T. Abel, and L.E. Hernquist. 2001. “Simulating Reionization in Numerical Cosmology.” New Astronomy 6 (6): 359–79. https://doi.org/10.1016/s1384-1076(01)00065-3.1384-10761384-1092http://nrs.harvard.edu/urn-3:HUL.InstRepos:41381722The incorporation of radiative transfer effects into cosmological hydrodynamical simulations is essential for understanding how the intergalactic medium (IGM) makes the transition from a neutral medium to one that is almost fully ionized. Here, we present an approximate numerical method designed to study in a statistical sense, how a cosmological density field is ionized by a set of discrete point sources. A diffuse background radiation field is also computed self-consistently in our procedure. The method requires relatively few time steps and can be employed with simulations having high resolution. We describe the details of the algorithm and provide a description of how the method can be applied to the output from a pre-existing cosmological simulation to study the systematic reionization of a particular ionic species. As a first application, we compute the reionization of He II by quasars in the range 3 less than or similar to z less than or similar to 6.en-USJournal Article2019-09-2010.1016/S1384-1076(01)00065-3