The Cosmic V-Web
Abstract
The network of filaments with embedded clusters surrounding voids seen in maps derived from redshift surveys and reproduced in simulations has been referred to as the cosmic web. A complementary description is provided by considering the shear in the velocity field of galaxies. The eigenvalues of the shear provide information on whether a region is collapsing in three dimensions, the condition for a knot, expanding in three-dimensions, the condition for a void, or in the intermediate condition of a filament or sheet. The structures that are quantitatively defined by the eigenvalues can be approximated by iso-contours that provide a visual representation of the cosmic velocity (V) web. The current application is based on radial peculiar velocities from the Cosmicflows-2 collection of distances. The three-dimensional velocity field is constructed using the Wiener filter methodology in the linear approximation. Eigenvalues of the velocity shear are calculated at each point on a grid. Here, knots and filaments are visualized across a local domain of diameter ~0.1c.
Keywords
Cite
@article{arxiv.1706.03413,
title = {The Cosmic V-Web},
author = {Daniel Pomarede and Yehuda Hoffman and Helene M Courtois and R. Brent Tully},
journal= {arXiv preprint arXiv:1706.03413},
year = {2017}
}
Comments
Accepted for publication in The Astrophysical Journal. Accompanied by a video and an interactive figure