Speaker
Description
Clusters present an excellent laboratory for studying influences on galaxy evolution due to their extreme environments that alter the evolutionary pathways of galaxies. However, the cluster does not have a clear boundary, which has motivated a number of studies proposing and identifying boundary definitions that capture various aspects of a halo’s properties. For example, the standard overdensity criteria identifies the boundary of a halo that encloses the necessary mass to virialize a halo and the splashback radius incorporates information on the orbital dynamics of halos. In this talk, I will discuss a study in which we classify galaxies as “field” or “cluster” galaxies based on intrinsic properties like star formation rate and stellar to halo mass ratio and relate this to their spatial distribution in the universe. We then obtain a probability that a galaxy is within a cluster’s influence based on its distance to the cluster center and compare this to various boundary definitions to identify which might capture the extent of a galaxy cluster’s environment on galaxy evolution. This can help inform cluster boundary decisions as well as indicate observational signatures and galaxy selections that can measure boundaries like the splashback radius.
