TY - JOUR
T1 - The sins/zC-sinf survey of z ∼ 2 galaxy kinematics
T2 - The nature of dispersion-dominated galaxies
AU - Newman, Sarah F.
AU - Genzel, Reinhard
AU - Förster Schreiber, Natascha M.
AU - Shapiro Griffin, Kristen
AU - Mancini, Chiara
AU - Lilly, Simon J.
AU - Renzini, Alvio
AU - Bouché, Nicolas
AU - Burkert, Andreas
AU - Buschkamp, Peter
AU - Carollo, C. Marcella
AU - Cresci, Giovanni
AU - Davies, Ric
AU - Eisenhauer, Frank
AU - Genel, Shy
AU - Hicks, Erin K.S.
AU - Kurk, Jaron
AU - Lutz, Dieter
AU - Naab, Thorsten
AU - Peng, Yingjie
AU - Sternberg, Amiel
AU - Tacconi, Linda J.
AU - Wuyts, Stijn
AU - Zamorani, Gianni
AU - Vergani, Daniela
PY - 2013/4/20
Y1 - 2013/4/20
N2 - We analyze the spectra, spatial distributions, and kinematics of Hα, [N II], and [S II] emission in a sample of 38, z ∼ 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 ∼ 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.
AB - We analyze the spectra, spatial distributions, and kinematics of Hα, [N II], and [S II] emission in a sample of 38, z ∼ 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 ∼ 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.
KW - galaxies: evolution
KW - galaxies: high-redshift
KW - infrared: galaxies
UR - http://www.scopus.com/inward/record.url?scp=84876120926&partnerID=8YFLogxK
U2 - 10.1088/0004-637X/767/2/104
DO - 10.1088/0004-637X/767/2/104
M3 - مقالة
SN - 0004-637X
VL - 767
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 104
ER -