We present deep observations of a z=1.4 massive, star-forming galaxy in molecular and ionized gas at comparable spatial resolution (CO 3-2, NOEMA; Hα, 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 fDM(≤Re)=0.18−0.04+0.06. Our result strengthens the evidence for strong baryon-dominance on galactic scales of massive z∼1−3 star-forming galaxies recently found based on ionized gas kinematics alone.
@article{arxiv.1802.02135,
title = {Ionized and molecular gas kinematics in a z=1.4 star-forming galaxy},
author = {Hannah D. N. Übler and Reinhard Genzel and Linda J. Tacconi and Natascha M. Förster Schreiber and Roberto Neri and Alessandra Contursi and Sirio Belli and Erica J. Nelson and Philipp Lang and T. Taro Shimizu and Ric Davies and Rodrigo Herrera-Camus and Dieter Lutz and Philipp M. Plewa and Sedona H. Price and Karl Schuster and Amiel Sternberg and Ken-ichi Tadaki and Emily Wisnioski and Stijn Wuyts},
journal= {arXiv preprint arXiv:1802.02135},
year = {2018}
}
Comments
accepted for publication in the Astrophysical Journal Letters