CONSTRAINING THE DYNAMICAL MASSES OF SPT2349-56: A MASSIVE GALAXY PROTOCLUSTER AT Z ∼ 4.3

Abstract

This study presents an analysis of SPT2349-56, the brightest unlensed source found by the South Pole Telescope during a 2500 deg^2 survey of the sky. Follow-up observations showed that SPT2349-56 is comprised of 14 Submillimeter Galaxies, all at the same redshift (z ∼ 4.3), suggesting that SPT2349-56 is a massive high redshift protocluster. Using this data, the kinematic properties from 12 galaxies within the protocluster were derived by probing the [CII] emission line. From these results, the mass of each source was measured from two different mass estimates: one based on the turbulence of the galaxy and the other based on the rotation of the galaxy. The mass estimates are compared to one another, and a new optimal mass estimate is provided for a range of galaxy environments. The mass fractions within each galaxy are also measured, as well as the total mass fraction for the protocluster as a whole.