Skip to main content

Research Repository

Advanced Search

The dynamics of z = 0.8 Hα-selected star-forming galaxies from KMOS/CF-HiZELS

Sobral, D.; Swinbank, A.M.; Stott, J.P.; Matthee, J.; Bower, R.G.; Smail, I.; Best, P.; Geach, J.E.; Sharples, R.M.

The dynamics of z = 0.8 Hα-selected star-forming galaxies from KMOS/CF-HiZELS Thumbnail


D. Sobral

J.P. Stott

J. Matthee

R.G. Bower

P. Best

J.E. Geach


We present the spatially resolved Hα dynamics of 16 star-forming galaxies at z ~ 0.81 using the new KMOS multi-object integral field spectrograph on the ESO Very Large Telescope. These galaxies, selected using 1.18 μm narrowband imaging from the 10 deg2 CFHT-HiZELS survey of the SA 22 hr field, are found in a ~4 Mpc overdensity of Hα emitters and likely reside in a group/intermediate environment, but not a cluster. We confirm and identify a rich group of star-forming galaxies at z = 0.813 ± 0.003, with 13 galaxies within 1000 km s–1 of each other, and seven within a diameter of 3 Mpc. All of our galaxies are "typical" star-forming galaxies at their redshift, 0.8 ± 0.4 SFR$^*_{z = 0.8}$, spanning a range of specific star formation rates (sSFRs) of 0.2-1.1 Gyr–1 and have a median metallicity very close to solar of 12 + log(O/H) = 8.62 ± 0.06. We measure the spatially resolved Hα dynamics of the galaxies in our sample and show that 13 out of 16 galaxies can be described by rotating disks and use the data to derive inclination corrected rotation speeds of 50-275 km s–1. The fraction of disks within our sample is 75% ± 8%, consistent with previous results based on Hubble Space Telescope morphologies of Hα-selected galaxies at z ~ 1 and confirming that disks dominate the SFR density at z ~ 1. Our Hα galaxies are well fitted by the z ~ 1-2 Tully-Fisher (TF) relation, confirming the evolution seen in the zero point. Apart from having, on average, higher stellar masses and lower sSFRs, our group galaxies at z = 0.81 present the same mass-metallicity and TF relation as z ~ 1 field galaxies and are all disk galaxies.


Sobral, D., Swinbank, A., Stott, J., Matthee, J., Bower, R., Smail, I., …Sharples, R. (2013). The dynamics of z = 0.8 Hα-selected star-forming galaxies from KMOS/CF-HiZELS. Astrophysical Journal, 779(2), Article 139.

Journal Article Type Article
Publication Date Dec 20, 2013
Deposit Date Dec 12, 2013
Publicly Available Date Jun 23, 2014
Journal Astrophysical Journal
Print ISSN 0004-637X
Electronic ISSN 1538-4357
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 779
Issue 2
Article Number 139
Keywords Galaxies: evolution, Galaxies: high-redshift, Galaxies: starburst.


Published Journal Article (836 Kb)

Copyright Statement
© 2013. The American Astronomical Society. All rights reserved.

You might also like

Downloadable Citations