THE SINS/zC-SINF SURVEY OF z {approx} 2GALAXY KINEMATICS: THE NATURE OF DISPERSION-DOMINATED GALAXIES

Journal Article · Sat Apr 20 00:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/767/2/104· OSTI ID:22126933

Newman, Sarah F.; Genzel, Reinhard ^[1]; Foerster Schreiber, Natascha M.; Buschkamp, Peter; Davies, Ric; Eisenhauer, Frank; Kurk, Jaron; Lutz, Dieter ^[2]; Shapiro Griffin, Kristen ^[3]; Mancini, Chiara; Renzini, Alvio ^[4]; Lilly, Simon J.; Carollo, C. Marcella; Peng, Yingjie ^[5]; Bouche, Nicolas ^[6]; Burkert, Andreas ^[7]; Cresci, Giovanni ^[8]; Genel, Shy ^[9]; Hicks, Erin K. S. ^[10]; Naab, Thorsten ^[11] ; others, and

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1. Department of Astronomy, Campbell Hall, University of California, Berkeley, CA 94720 (United States)
2. Max-Planck-Institut fuer extraterrestrische Physik (MPE), Giessenbachstr. 1, D-85748 Garching (Germany)
3. Space Sciences Research Group, Northrop Grumman Aerospace Systems, Redondo Beach, CA 90278 (United States)
4. Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, Padova I-35122 (Italy)
5. Institute of Astronomy, Department of Physics, Eidgenoessische Technische Hochschule, ETH Zuerich CH-8093 (Switzerland)
6. Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France)
7. Universitaets-Sternwarte Ludwig-Maximilians-Universitaet (USM), Scheinerstr. 1, Muenchen D-81679 (Germany)
8. Istituto Nazionale di Astrofisica Osservatorio Astronomico di Arcetri, Largo Enrico Fermi 5, I-50125 Firenze (Italy)
9. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
10. Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States)
11. Max-Planck Institute for Astrophysics, Karl Schwarzschildstrasse 1, D-85748 Garching (Germany)

We analyze the spectra, spatial distributions, and kinematics of H{alpha}, [N II], and [S II] emission in a sample of 38, z {approx} 2.2 UV/optically selected star-forming galaxies (SFGs) from the SINS and zC-SINF surveys, 34 of which were observed in the adaptive optics mode of SINFONI and 30 of those contain data presented for the first time here. This is supplemented by kinematic data from 43 z {approx} 1-2.5 galaxies from the literature. None of these 81 galaxies is an obvious major merger. We find that the kinematic classification of high-z SFGs as ''dispersion dominated'' or ''rotation dominated'' correlates most strongly with their intrinsic sizes. Smaller galaxies are more likely ''dispersion-dominated'' for two main reasons: (1) the rotation velocity scales linearly with galaxy size but intrinsic velocity dispersion does not depend on size or may even increase in smaller galaxies, and as such, their ratio is systematically lower for smaller galaxies, and (2) beam smearing strongly decreases large-scale velocity gradients and increases observed dispersion much more for galaxies with sizes at or below the resolution. Dispersion-dominated SFGs may thus have intrinsic properties similar to ''rotation-dominated'' SFGs, but are primarily more compact, lower mass, less metal enriched, and may have higher gas fractions, plausibly because they represent an earlier evolutionary state.

• OSTI ID: 22126933
• Journal Information: Astrophysical Journal, Vol. 767, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BEAMS
CLASSIFICATION
DISPERSIONS
EMISSION
GALAXIES
RED SHIFT
ROTATION
SPATIAL DISTRIBUTION
SPECTRA
STARS
VELOCITY