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ALMA ACA CO Observations in Isolated Galaxy Pairs: the Low Mass Picture

POSTER

Abstract

Analyses of pair galaxy interactions provide a critical picture of dynamics influencing gas and stellar buildup in low-mass, metal-poor environments. Previous probing of low-redshift TiNY Titans dwarf galaxy pairs (10$^{7}$ M$_{\odot}$ $<$ M $<$ 10$^{9.7}$ M$_{\odot}$; 8.0 $<$ Z $<$ 8.9) via the Sloan Digital Sky Survey found enhanced star formation rates with separation distances R$_{sep}$ $<$ ~100 kpc. Whether this star formation is a result of an increased H$_{2}$ mass or efficiency in which the H$_{2}$ is converted to stars remains unclear. For the first time, we present ALMA Atacama Compact Array molecular gas quantities of these dwarf galaxy pair systems with close separations (6 kpc $<$ R$_{sep}$ $<$ 48 kpc) via the CO tracer. CO is detected in four galaxies, and an application of the Milky Way accepted $\alpha_{CO}$ results in molecular gas calculations of ~10$^{8}$ M$_{\odot}$. A comparison of molecular gas and stellar formation rate to the xCOLDGASS (10$^{9}$ M$_{\odot}$ $<$ M $<$ 10$^{11.5}$ M$_{\odot}$) data set does not identify higher H$_{2}$ nor efficiency in these dwarfs. This preliminary study thus demonstrates the feasibility of measuring H$_{2}$ reservoirs in dwarfs, with future studies aimed at constraining molecular gas mass at lower metallicity environments.

Authors

  • Swetha Sankar

    University of California, Los Angeles

  • George Privon

    National Radio Astronomy Observatory

  • Kristin Rabosky

    Middle Tennessee State University, University of Alabama Tuscaloosa, Swarthmore College, CT Clinical Innovation Center, Department of Radiology, Mayo Clinic, Rochester, MN, Bard College, Wright State University, University of Michigan, University of Hawai&#039;i-Manoa, Rice University, University of Alaska Fairbanks, University of Utah, South Dakota School of Mines and Technology, Furman University, University of Notre Dame, Theoretical Physics Division, Institute of High Energy Physics, the Chinese Academy of Sciences, Peng Huanwu Center for Fundamental Theory, University of Science and Technology China, University of Cambridge, University of Kansas, SLAC National Accelerator Laboratory, Planetary Science Institute, Iowa State University, College of Idaho, University of Washington, Bothell, Ottawa Hills High School, Case Western Reserve University, Yale University and Strasbourg Astronomical Observatory, Yale University, Korea Astronomy and Space Science Institute, NOIRLab, Purdue University, Korea Instotute for Advanced Study, Perimeter Institute, Rutgers University, University of Maryland, Juniata College, Columbia University, City University of New York / American Museum of Natural History, Columbia University / American Museum of Natural History, Morehead State University, Hofstra University, Occidental College, Georgia Institute of Technology, School of Physics and Astronomy, University of Minnesota, The Oskar Klein Centre, Department of Astronomy, University of Mississippi, Stanford/KIPAC/SLAC, University of Connecticut, Kansas State University, Vassar College, Penn State, Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Department of Physics, Worcester Polytechnic Institute, Clark University, University of Illinois at Urbana-Champaign, Rhodes College, Rensselaer Polytechnic Institute, Harvard University, Cornell University, Air Force Research Lab, Wright-Patterson AFB, Ohio 45433, Air Force Research Lab, Wright-Patterson AFB, Ohio 45433 & UES, Inc., 4401 Dayton-Xenia Rd, Dayton, OH 45432, Department of Physics, University of Dayton, Dayton Ohio & Air Force Research Lab, Wright-Patterson AFB, Ohio 45433, Los Alamos National Laboratory, Utah State University, Ramapo College of NJ, Brookhaven National Laboratory, Research Center of Topological Functional Materials and Henan Key Laboratory of Photovoltaic Materials, Henan Univers., Brookhaven National Laboratory, Montclair State University, Weber State University