The Size, Shape and Orientation of Cosmological Voids in the Sloan Digital Sky Survey

Caroline Foster, Lorne A. Nelson

Published 2009-04-30, updated 2009-06-23Version 3

We present a detailed description of our void finding algorithm which is an extension of the prescription by Hoyle and Vogeley (2002). We include a discussion of the reproducibility and robustness of the algorithm as well as the statistical significance of the detected voids. We apply our void finder to the Data Release 5 (DR5) of the Sloan Digital Sky Survey (SDSS) and identify 232 cosmological voids. A void catalog which contains the most salient properties of the detected voids is created. We present a statistical analysis of the distribution of the size, shape and orientation of our identified cosmological voids. We also investigate possible trends with redshift for 0.04 < z < 0.16. We compare our results to those from an identical analysis of a mock catalog based on the LambdaCDM model and find reasonable agreement. However, some statistically significant differences in the overall orientation of cosmological voids are present and will have to be reconciled by further refinement of the simulations.