Ionized and Molecular Gas Kinematics in a z = 1.4 Star-forming Galaxy
Lutz, D.; Wuyts, S.; Förster Schreiber, N. M.; Genzel, R.; Tacconi, L. J.; Contursi, A.; Nelson, E. J.; Lang, P.; Sternberg, A.; Neri, R.; Schuster, K.; Davies, R.; Tadaki, K.; Übler, H.; Wisnioski, E.; Herrera-Camus, R.; Belli, S.; Price, S. H.; Shimizu, T. T.; Plewa, P. M.
Germany, United States, France, Israel, Japan, Australia, United Kingdom
Abstract
We present deep observations of a z = 1.4 massive, star-forming galaxy (SFG) in molecular and ionized gas at comparable spatial resolution (CO 3-2, NOrthern Extended Millimeter Array (NOEMA); Hα, Large Binocular Telescope (LBT)). The kinematic tracers agree well, indicating that both gas phases are subject to the same gravitational potential and physical processes affecting the gas dynamics. We combine the one-dimensional velocity and velocity dispersion profiles in CO and Hα to forward-model the galaxy in a Bayesian framework, combining a thick exponential disk, a bulge, and a dark matter halo. We determine the dynamical support due to baryons and dark matter, and find a dark matter fraction within one effective radius of {f}DM}(≤slant {R}e)={0.18}-0.04+0.06. Our result strengthens the evidence for strong baryon-dominance on galactic scales of massive z ∼ 1-3 SFGs recently found based on ionized gas kinematics alone.
Based on observations carried out with the IRAM Interferometer NOEMA. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain). Based on observations carried out with the LBT. The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, The Leibniz Institute for Astrophysics Potsdam, and Heidelberg University; The University of Arizona on behalf of the Arizona Board of Regents; Istituto Nazionale di Astrofisica, Italy; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota and University of Virginia.