Catalogues of voids as antihalos in the local Universe

TL;DR

This paper applies a novel void identification algorithm, based on inverting the initial density field, to real universe simulations, producing extensive catalogs of cosmic voids called antihalos and analyzing their properties.

Contribution

It extends the antihalo void identification method from simulations to real universe data using constrained simulations and provides detailed statistical analyses of the resulting voids.

Findings

Identified ~150,000 voids as antihalos per simulation

Analyzed size, shape, density, and clustering of voids

Compared antihalo voids with VIDE catalogues

Abstract

A recently-proposed algorithm identifies voids in simulations as the regions associated with halos when the initial overdensity field is negated. We apply this method to the real Universe by running a suite of constrained simulations of the 2M++ volume with initial conditions inferred by the BORG algorithm, along with the corresponding inverted set. Our 101 inverted and uninverted simulations, spanning the BORG posterior, each identify ~150,000 "voids as antihalos" with mass exceeding $4.38\times10^{11} \: \mathrm{M_\odot}$ (100 particles) at $z=0$ in a full-sky sphere of radius 155 Mpc/h around the Milky Way. We calculate the size function, volume filling fraction, ellipticity, central density, specific angular momentum, clustering and stacked density profile of the voids, and cross-correlate them with those produced by VIDE on the same simulations. We make our antihalo and VIDE catalogues publicly available.