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Title: The SINS/zC-SINF survey of z ∼ 2 galaxy kinematics: Evidence for gravitational quenching

As part of the SINS/zC-SINF surveys of high-z galaxy kinematics, we derive the radial distributions of Hα surface brightness, stellar mass surface density, and dynamical mass at ∼2 kpc resolution in 19 z ∼ 2 star-forming disks with deep SINFONI adaptive optics spectroscopy at the ESO Very Large Telescope. From these data we infer the radial distribution of the Toomre Q-parameter for these main-sequence star-forming galaxies (SFGs), covering almost two decades of stellar mass (10{sup 9.6}-10{sup 11.5} M {sub ☉}). In more than half of our SFGs, the Hα distributions cannot be fit by a centrally peaked distribution, such as an exponential, but are better described by a ring, or the combination of a ring and an exponential. At the same time the kinematic data indicate the presence of a mass distribution more centrally concentrated than a single exponential distribution for 5 of the 19 galaxies. The resulting Q-distributions are centrally peaked for all, and significantly exceed unity there for three-quarters of the SFGs. The occurrence of Hα rings and of large nuclear Q-values appears to be more common for the more massive SFGs. While our sample is small and biased to larger SFGs, and there remain uncertainties and caveats,more » our observations are consistent with a scenario in which cloud fragmentation and global star formation are secularly suppressed in gas-rich high-z disks from the inside out, as the central stellar mass density of the disks grows.« less
Authors:
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  1. Max-Planck-Institut für Extraterrestrische Physik (MPE), Giessenbachstr.1, D-85748 Garching (Germany)
  2. Institute for Astronomy, Department of Physics, Eidgenössische Technische Hochschule, ETH Zürich, 8093-CH (Switzerland)
  3. Istituto Nazionale di Astrofisica—Osservatorio Astronomico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy)
  4. Department of Physics and Astronomy, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99507 (United States)
  5. Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy)
  6. Max-Planck Institute for Astrophysics, Karl Schwarzschildstrasse 1, D-85748 Garching (Germany)
  7. Department of Astronomy, Campbell Hall, University of California, Berkeley, CA 94720 (United States)
Publication Date:
OSTI Identifier:
22357139
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 785; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BRIGHTNESS; COSMOLOGY; DENSITY; EVOLUTION; FRAGMENTATION; GALAXIES; MAIN SEQUENCE STARS; MASS; MASS DISTRIBUTION; QUENCHING; Q-VALUE; RED SHIFT; RESOLUTION; SPECTROSCOPY; SURFACES; TELESCOPES