Subhalo Abundance Matching And Its Cosmological Applications

TYPEAstrophysics Seminar
Speaker:Vimal Simha
Affiliation:Durham University
Organizer:Hagai Perets
Time:14:30 - 15:30
Location:Lidow 620
Abstract:Subhalo abundance matching (SHAM) is a technique for assigning luminosities to simulated dark matter substructures by assuming a strictly monotonic relationship between galaxy luminosity and halo mass at the epoch of accretion. We carry out matched N-body and smoothed particle hydrodynamics (SPH) simulations of a cosmological volume, finding good agreement between SHAM and SPH galaxy stellar masses and luminosities at a wide range of epochs, albeit with relatively small amounts of scatter. By populating N-body simulations with galaxies using SHAM, we generate predictions for the clustering of galaxies as a function of cosmology, and use this to place constraints on the matter density of the Universe ( ΩM ) and the amplitude of clustering (σ8). This technique provides a powerful constraint on the cosmological parameters using only low redshift data that is complementary to other commonly used methods.