Splashback Radius of Groups and Galaxies

Abstract

Traditionally, halo radii have been defined based on the spherical over density criterion where the halo radius encloses some over density with respect to the critical or mean density of the universe, leading to definitions such as R200c, R200m, and Rvir. Splashback Radius is a proposed, physically motivated definition of halo boundary. It is the radius at which infalling material reaches its first apocenter in a halo. N-body simulations have shown the existence of this feature. Observational evidence of the feature is the next challenge, especially for halos below cluster mass scale. My work includes attempts to bring out this feature for group mass galaxies in the Dark Energy Survey, and study it in different environments of the universe.