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arXiv · 1802.02135

Ionized and molecular gas kinematics in a z=1.4 star-forming galaxy

Hannah D. N. Übler·Reinhard Genzel·Linda J. Tacconi·Natascha M. Förster Schreiber·Roberto Neri·Alessandra Contursi·Sirio Belli·Erica J. Nelson·Philipp Lang·T. Taro Shimizu·Ric Davies·Rodrigo Herrera-Camus·Dieter Lutz·Philipp M. Plewa·Sedona H. Price·Karl Schuster·Amiel Sternberg·Ken-ichi Tadaki·Emily Wisnioski·Stijn Wuyts
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Abstract

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; H$\alpha$, 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 H$\alpha$ 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_{\rm DM}(\leq$$R_{e})=0.18^{+0.06}_{-0.04}$. Our result strengthens the evidence for strong baryon-dominance on galactic scales of massive $z\sim1-3$ star-forming galaxies recently found based on ionized gas kinematics alone.

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Hannah D. N. Übler, Reinhard Genzel, Linda J. Tacconi, Natascha M. Förster Schreiber, Roberto Neri, Alessandra Contursi, Sirio Belli, Erica J. Nelson, Philipp Lang, T. Taro Shimizu, Ric Davies, Rodrigo Herrera-Camus, Dieter Lutz, Philipp M. Plewa, Sedona H. Price, Karl Schuster, Amiel Sternberg, Ken-ichi Tadaki, Emily Wisnioski, Stijn Wuyts. 2018-02-06. Ionized and molecular gas kinematics in a z=1.4 star-forming galaxy. https://doi.org/10.3847/2041-8213/aaacfa

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