The Alignment of Dark Matter Halos with the Cosmic Web

Abstract

We investigate the orientation of the axes and angular momentum of dark matter halos with respect to their neighboring voids using high-resolution N-body cosmological simulations. We find that the minor axis of a halo tends to be aligned along the line joining the halo with the center of the void and that the major axis tends to lie in the plane perpendicular to this line. However, we find that the angular momentum of a halo does not have any particular orientation. These results may provide information about the mechanisms whereby the large-scale structure of the universe affects galaxy formation, and they may cast light on the issue of the orientation of galaxy disks with respect to their host halos.