Predoctoral Projects, 2015

Project Title: The Star Formation Reference Survey

Project Advisor: Dr. Matthew L. N. Ashby

Background: Star formation has been the most important single physical process since recombination. It is fundamental to galaxy formation and evolution. Not only have stars created most of the luminous energy in the universe, they have produced the heavy elements needed for planets and life. Star formation has naturally been the subject of intense study, leading, for example, to our current understanding of the star formation history of the universe (eg., Lilly etal 1996, Hopkins Beacom 1996, Madau etal 1998) and the discovery of the Schmidt Law (Schmidt 1959 updated by Kennicutt etal 1998) relating galaxies star formation rate (SFR) to the local gas surface density.

Scientific Questions: Despite these advances, there are gaps in our understanding. A general inadequacy of existing work in this field is the lack of a self-consistent treatment/measurement of SFR across the full SEDs of galaxies. This is what our Reference Survey aims to provide. Doing so will help us to better understand 1) the meaning of various SF metrics in relation to fundamental galaxy parameters, 2) the prevalence of active galactic nuclei (AGN) within SF galaxies and AGN/SF interplay, and 3) all manifestations of SF in the local universe, which in turn will serve as systematic benchmarks for SF in the distant universe.

Scientific Methodology: Dr. Ashby is leading an international team of astronomers now engaged in gathering and analyzing panchromatic data for a representative sample of about 400 star-forming galaxies in the local universe. The sample has been carefully constructed so that it contains all existing modes of star formation known to exist in the local universe. Specifically, it spans seven decades in luminosity, a factor of 200 in star forming intensity, and the entire range of galaxy mass and dust temperature.

Other links related to this project


Clay Fellow Warren Brown