Collaborative Research: The GOGREEN Survey - Caring about the Environment

University Of California-Riverside, Riverside CA

Investigators

Abstract

The team will use ground-based telescopes to study the vast population of "satellite" galaxies that live in the suburbs of cities of galaxies called clusters. We know that satellite galaxies can transform themselves from bluish systems rife with brilliant, young stars into reddish systems filled with dull, old stars. But models that attempt explain this remarkable transformation fail dismally. This means that the modellers need much more guidance about factors that govern a galaxy's life in the suburbs. The team will provide that important guidance. The team will also expand existing, successful outreach programs at their institutions. Areas of emphasis include high school students using the new data to conduct inquiry-based research, school teachers adding evidence-based research into their lesson plans, deaf students "smelling" and "touching" data that have been suitably transformed, and Hispanic students being encouraged to continue on from college to graduate school. The aim of the project is to examine the physical processes responsible for quenching the star formation in clusters' satellite galaxies, as distinct from their central galaxies. Models of central-galaxy quenching agree well with observations. In contrast, models of satellite-galaxy quenching strongly violate observations, meaning that such models need better guidance about the processes involved. The team will provide that guidance by obtaining new spectroscopic data for massive groups and clusters at redshifts of 1-1.5 and comparing those data to existing lower-redshift data. These comparisons will be used to analyze the dominant modes of satellite quenching, how galaxies populate dark-matter halos as a function of environment, the relative timing of morphological transformation and star-formation quenching, and the dominant driver of size growth in quenched galaxies. These results will lead to new, better-informed models of satellite-galaxy quenching.