Star Formation Rate Indicators in the FIRE simulations & SPT2349-56: A Massive and Active Proto-cluster Core

Abstract

Part 1) The star formation rate (SFR) is an important diagnostic of the evolutionary stage of the galaxy. The total infrared (IR) luminosity of a galaxy is a commonly used tracer of SFR. A simple radiative transfer model to estimate the IR luminosity is applied to the feedback in realistic environments (FIRE) simulation suite. The connection between IR luminosity and SFR compared to a well-established model. A large amount of scatter and systematic bias cautions against the interpretations of observations from this simple model. Part 2) Studying progenitors of galaxy clusters (proto-clusters) presents an exciting opportunity to study star formation in extreme environments in the early universe. Detailed follow-up observations the proto-cluster SPT2349-56 is presented. SPT2349-56 contains 12 star forming galaxies in an extremely confined radius. Our observations suggest that SPT2349-56 an especially active and massive proto-cluster. Comparison with other known proto-cluster systems shows that SPT2349-56 is truly unique.