SIMULATED VOID GALAXIES IN THE STANDARD COLD DARK MATTER MODEL

We analyze a (120 h(-1) Mpc)(3) adaptive mesh refinement hydrodynamic simulation that contains a higher resolution 31 x 31 x 35 h(-3) Mpc subvolume centered on a similar to 30 Mpc diameter void. Our detailed similar to 1 kpc resolution allows us to identify 1300 galaxies within this void to a limiting halo mass of similar to 10(10) M-circle dot. Nearly 1000 galaxies are found to be in underdense regions, with 300 galaxies residing in regions less than half the mean density of the simulation volume. We construct mock observations of the stellar and gas properties of these systems and reproduce the range of colors and luminosities observed in the Sloan Digital Sky Survey for nearby (z < 0.03) galaxies. We find no trends with density for the most luminous (M-r < -18) galaxies, however our dwarf void galaxies (M-r > -16), though they are less reliably resolved, typically appear bluer, with higher rates of star formation and specific star formation and lower mean stellar ages than galaxies in average density environments. We find a significant population of low-luminosity (M-r similar to -14) dwarf galaxies that is preferentially located in low-density regions and specifically in the void center. This population may help to reduce, but not remove, the discrepancy between the predicted and observed number of void galaxies.