GBT17B-151

Extragalactic GBT+ARGUS Gas Density Survey

Abstract

Every major current theory of star formation in galaxies treats gas density as a central quantity. Differentiating between these theories requires (1) quantifying the relationship between gas density and star formation and (2) understanding what sets the gas density distribution within a galaxy. We propose the new capabilities of ARGUS to map a suite of density-sensitive mm-wave lines (HCN 1-0, HCO+ 1-0, C18O 1-0, and 13CO 1-0) across the inner 2arcmin by 2arcmin of 36 nearby galaxies. We will use these lines to measure how the gas volume density distribution changes as a function of galactic environment and, by comparing the changing density distribution to the rate of recent star formation, evaluate how density affects the ability of gas to form stars. These observations will produce a high impact, best-in-class survey of how the gas density distribution changes across galaxies, strong tests of the current leading theories of star formation in galaxies, and measurements that bridge the gap between Milky Way and extragalactic studies. This is a resubmission of a highly ranked proposal that was awarded up to 167h hours in 17A. We have incorporated the on-sky performance of ARGUS and highlighted the NSF grant support available for this program.

Investigators

Name	Institution
Amanda Kepley *	National Radio Astronomy Observatory
Antonio Usero	Instituto Geográfico Nacional
Dave Frayer	Green Bank Observatory
Molly Gallagher	Ohio State University
Karin Sandstrom	California at San Diego, University of; Arizona, University of; Max-Planck-Institut für Astronomie
Yiqing Song	Virginia, University of; European Southern Observatory
Matteo Luisi	Westminster College
Eric Koch	Alberta, University of; Smithsonian Astrophysical Observatory
Jeremy Thorley
Joy Skipper	Green Bank Observatory
Jennifer Donovan Meyer	National Radio Astronomy Observatory
Dongwoo Chung	Stanford University
Rebecca Levy	Space Telescope Science Institute
Alberto Bolatto	Maryland, University of
Sarah Church	Stanford University
Joshua Gundersen	Miami, University of
Cheoljong Lee	Virginia, University of
Adam Leroy	National Radio Astronomy Observatory; Ohio State University
Jialu Li	Maryland, University of
Maria Jesus Jimenez Donaire	Instituto Geográfico Nacional; Yebes, Centro Astronómico de
Andreas Schruba	Max-Planck-Institut für extraterrestrische Physik
Eva Schinnerer	National Radio Astronomy Observatory; Max-Planck-Institut für Astronomie
Andy Harris	Maryland, University of
Erik Rosolowsky	British Columbia at Okanagan, University of ; Alberta, University of
Frank Bigiel	Bonn, Universität
Matthew Sieth	Stanford University
Sarah Kessler	Ohio State University
Luca Beale	Virginia, University of
Kieran Cleary	California Institute of Technology
Annie Hughes	Max-Planck-Institut für Astronomie; Centre National de la Recherche Scientifique

* indicates the PI