The SINS/zC-SINF Survey of z~2 Galaxy Kinematics: The Nature of Dispersion Dominated Galaxies

Дата и время публикации : 2012-11-26T23:21:45Z

Авторы публикации и институты :
Sarah F. Newman
Reinhard Genzel
Natascha M. Forster Schreiber
Kristen Shapiro Griffin
Chiara Mancini
Simon J. Lilly
Alvio Renzini
Nicolas Bouche
Andreas Burkert
Peter Buschkamp
C. Marcella Carollo
Giovanni Cresci
Ric Davies
Frank Eisenhauer
Shy Genel
Erin K. S. Hicks
Jaron Kurk
Dieter Lutz
Thorsten Naab
Yingjie Peng
Amiel Sternberg
Linda J. Tacconi
Stijn Wuyts
Gianni Zamorani
Daniela Vergani

Ссылка на журнал-издание: 2013, ApJ 767, 104
Коментарии к cтатье: 13 pages, 9 figures, accepted by ApJ
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO

Краткий обзор статьи: We analyze the spectra, spatial distributions and kinematics of Ha, [NII] and [SII] emission in a sample of 42, z~2.2 UV/optically selected star forming galaxies (SFGs) from the SINS & zC-SINF surveys, 35 of which were observed in the adaptive optics mode of SINFONI. This is supplemented by kinematic data from 48 z~1-2.5 galaxies from the literature. We find that the kinematic classification of the 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, 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.

Category: Physics