DruckenThe Structure of Supervoids I: Void Hierarchy in the Northern Local Supervoid
Astronomy & Astrophysics (accepted) Contact: ulindner@uni-sw.gwdg.de Preprint of paper
Ulrich Lindner [1], Jaan Einasto [2], Maret Einasto [2],
Wolfram Freudling [3,4], Klaus Fricke [1], Erik Tago [2]
Abstract
Supervoids are regions in the local Universe which do not
contain rich clusters of galaxies. In order to investigate
the distribution of galaxies in and around supervoids, we
have studied the closest example, the Northern Local Void.
It is defined as the region between the Local, Coma, and the
Hercules superclusters, which is well covered by available
redshift surveys.
We find that this supervoid is not empty, but it contains
small galaxy systems and poor clusters of galaxies. We study
the cosmography of this void by analyzing the distribution
of poor clusters of galaxies, elliptical and other galaxies
in two projections. We present a catalogue of voids, defined
by galaxies of different morphological type and luminosity,
and analyze mean diameters of voids in different environments.
This analysis shows that sizes of voids and properties of void
walls are related. Voids defined by poor clusters of galaxies and
by bright elliptical galaxies have a mean diameter of up to 40
h-1 Mpc. Faint late-type galaxies divide these voids into smaller
voids. The faintest galaxies we can study are outlining voids
with mean diameters of about 8 h-1 Mpc. Voids located in a high-
density environment are smaller than voids in low-density regions.
The dependence of void diameters on the type and luminosity of
galaxies, as well as on the large-scale environment shows that voids
form a hierarchical system.
Key words:
cosmology: observations - galaxies: clustering - large-scale structure
of the Universe
