Universal void density profiles from simulation and SDSS

TL;DR

This paper demonstrates that void density profiles are universal and self-similar across simulations and SDSS observations, revealing a fundamental property of voids identified by watershed algorithms.

Contribution

It shows the universality and self-similarity of void density profiles in both simulated and real galaxy data, across various luminosities and redshifts.

Findings

Void profiles are self-similar and independent of size and redshift.

Excellent match between simulated and real void profiles.

Universal behavior of voids across different galaxy luminosities and densities.

Abstract

We discuss the universality and self-similarity of void density profiles, for voids in realistic mock luminous red galaxy (LRG) catalogues from the Jubilee simulation, as well as in void catalogues constructed from the SDSS LRG and Main Galaxy samples. Voids are identified using a modified version of the ZOBOV watershed transform algorithm, with additional selection cuts. We find that voids in simulation are self-similar, meaning that their average rescaled profile does not depend on the void size, or -- within the range of the simulated catalogue -- on the redshift. Comparison of the profiles obtained from simulated and real voids shows an excellent match. The profiles of real voids also show a universal behaviour over a wide range of galaxy luminosities, number densities and redshifts. This points to a fundamental property of the voids found by the watershed algorithm, which can be exploited in future studies of voids.