Cosmic voids in Sloan Digital Sky Survey Data Release 7

We study the distribution of cosmic voids and void galaxies using Sloan Digital Sky Survey Data Release 7 (SDSS DR7). Using the VoidFinder algorithm based on the original VoidFinder method devised by El-Ad & Piran and implemented by Hoyle & Vogeley, we identify 1054 statistically significant voids in the Northern galactic hemisphere with radii >10 h(-1) Mpc. The filling factor of voids in the sample volume is 62 per cent. The largest void is just over 30 h-1 Mpc in effective radius. The median effective radius is 17 h-1 Mpc. The voids are found to be significantly underdense, with density contrast delta < -0.85 at the edges of the voids. The radial-density profiles of these voids are similar to predictions of dynamically distinct underdensities in gravitational theory. We find 8046 galaxies brighter than M-r = -20.09 within the voids, accounting for 7 per cent of the galaxies. We compare the results of VoidFinder on SDSS DR7 to mock catalogues generated from a smoothed particle hydrodynamics (SPH) halo model simulation as well as other Lambda cold dark matter (Lambda CDM) simulations and find similar void fractions and void sizes in the data and simulations. This catalogue is made publicly available at http://www.physics.drexel.edu/similar to pan/VoidCatalog for download.