The KMOS3D Survey: Rotating Compact Star-forming Galaxies and the Decomposition of Integrated Line Widths

Wisnioski, E.; Mendel, J.T.; Förster Schreiber, N.M.; Genzel, R.; Wilman, D.; Wuyts, S.; Belli, S.; Beifiori, A.; Bender, R.; Brammer, G.; Chan, J.; Davies, R.I.; Davies, R.L.; Fabricius, M.; Fossati, M.; Galametz, A.; Lang, P.; Lutz, D.; Nelson, E.J.; Momcheva, I.; Rosario, D.; Saglia, R.; Tacconi, L.J.; Tadaki, K.; Übler, H.; van Dokkum, P.G.

doi:10.3847/1538-4357/aab097

The KMOS3D Survey: Rotating Compact Star-forming Galaxies and the Decomposition of Integrated Line Widths

Wisnioski, E.; Mendel, J.T.; Förster Schreiber, N.M.; Genzel, R.; Wilman, D.; Wuyts, S.; Belli, S.; Beifiori, A.; Bender, R.; Brammer, G.; Chan, J.; Davies, R.I.; Davies, R.L.; Fabricius, M.; Fossati, M.; Galametz, A.; Lang, P.; Lutz, D.; Nelson, E.J.; Momcheva, I.; Rosario, D.; Saglia, R.; Tacconi, L.J.; Tadaki, K.; Übler, H.; van Dokkum, P.G.

Authors

E. Wisnioski

J.T. Mendel

N.M. Förster Schreiber

R. Genzel

D. Wilman

S. Wuyts

S. Belli

A. Beifiori

R. Bender

G. Brammer

J. Chan

R.I. Davies

R.L. Davies

M. Fabricius

M. Fossati

A. Galametz

P. Lang

D. Lutz

E.J. Nelson

I. Momcheva

D. Rosario

R. Saglia

L.J. Tacconi

K. Tadaki

H. Übler

P.G. van Dokkum

Abstract

Using integral field spectroscopy, we investigate the kinematic properties of 35 massive centrally dense and compact star-forming galaxies (SFGs; $\mathrm{log}{\overline{M}}_{* }[{M}_{\odot }]=11.1$, $\mathrm{log}({{\rm{\Sigma }}}_{1\mathrm{kpc}}[{M}_{\odot }\,{\mathrm{kpc}}^{-2}])\gt 9.5$, $\mathrm{log}({M}_{* }/{r}_{e}^{1.5}[{M}_{\odot }\,{\mathrm{kpc}}^{-1.5}])\gt 10.3$) at z ~ 0.7–3.7 within the KMOS3D survey. We spatially resolve 23 compact SFGs and find that the majority are dominated by rotational motions with velocities ranging from 95 to 500 km s−1. The range of rotation velocities is reflected in a similar range of integrated Hα line widths, 75–400 km s−1, consistent with the kinematic properties of mass-matched extended galaxies from the full KMOS3D sample. The fraction of compact SFGs that are classified as "rotation-dominated" or "disklike" also mirrors the fractions of the full KMOS3D sample. We show that integrated line-of-sight gas velocity dispersions from KMOS3D are best approximated by a linear combination of their rotation and turbulent velocities with a lesser but still significant contribution from galactic-scale winds. The Hα exponential disk sizes of compact SFGs are, on average, 2.5 ± 0.2 kpc, 1–2× the continuum sizes, in agreement with previous work. The compact SFGs have a 1.4× higher active galactic nucleus (AGN) incidence than the full KMOS3D sample at fixed stellar mass with an average AGN fraction of 76%. Given their high and centrally concentrated stellar masses, as well as stellar-to-dynamical mass ratios close to unity, the compact SFGs are likely to have low molecular gas fractions and to quench on a short timescale unless replenished with inflowing gas. The rotation in these compact systems suggests that their direct descendants are rotating passive galaxies.

Citation

Wisnioski, E., Mendel, J., Förster Schreiber, N., Genzel, R., Wilman, D., Wuyts, S., …van Dokkum, P. (2018). The KMOS3D Survey: Rotating Compact Star-forming Galaxies and the Decomposition of Integrated Line Widths. Astrophysical Journal, 855(2), Article 97. https://doi.org/10.3847/1538-4357/aab097

Journal Article Type	Article
Acceptance Date	Feb 16, 2018
Online Publication Date	Mar 12, 2018
Publication Date	Mar 12, 2018
Deposit Date	Apr 9, 2018
Publicly Available Date	Apr 9, 2018
Journal	Astrophysical Journal
Print ISSN	0004-637X
Electronic ISSN	1538-4357
Publisher	American Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	855
Issue	2
Article Number	97
DOI	https://doi.org/10.3847/1538-4357/aab097