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The KMOS Redshift One Spectroscopic Survey (KROSS): the origin of disc turbulence in z ≈ 1 star-forming galaxies

Johnson, H.L.; Harrison, C.M.; Swinbank, A.M.; Tiley, A.L.; Stott, J.P.; Bower, R.G.; Smail, I.; Bunker, A.J.; Sobral, D.; Turner, O.J.; Best, P.; Bureau, M.; Cirasuolo, M.; Jarvis, M.J.; Magdis, G.; Sharples, R.M.; Bland-Hawthorn, J.; Catinella, B.; Cortese, L.; Croom, S.M.; Federrath, C.; Glazebrook, K.; Sweet, S.M.; Bryant, J.J.; Goodwin, M.; Konstantopoulos, I.S.; Lawrence, J.S.; Medling, A.M.; Owers, M.S.; Richards, S.

The KMOS Redshift One Spectroscopic Survey (KROSS): the origin of disc turbulence in z ≈ 1 star-forming galaxies Thumbnail


Authors

H.L. Johnson

C.M. Harrison

A.M. Swinbank

A.L. Tiley

J.P. Stott

R.G. Bower

A.J. Bunker

D. Sobral

O.J. Turner

P. Best

M. Bureau

M. Cirasuolo

M.J. Jarvis

G. Magdis

J. Bland-Hawthorn

B. Catinella

L. Cortese

S.M. Croom

C. Federrath

K. Glazebrook

S.M. Sweet

J.J. Bryant

M. Goodwin

I.S. Konstantopoulos

J.S. Lawrence

A.M. Medling

M.S. Owers

S. Richards



Abstract

We analyse the velocity dispersion properties of 472 z ∼ 0.9 star-forming galaxies observed as part of the KMOS Redshift One Spectroscopic Survey (KROSS). The majority of this sample is rotationally dominated (83 ± 5 per cent with vC/σ0 > 1) but also dynamically hot and highly turbulent. After correcting for beam smearing effects, the median intrinsic velocity dispersion for the final sample is σ0 = 43.2 ± 0.8 km s−1 with a rotational velocity to dispersion ratio of vC/σ0 = 2.6 ± 0.1. To explore the relationship between velocity dispersion, stellar mass, star formation rate, and redshift, we combine KROSS with data from the SAMI survey (z ∼ 0.05) and an intermediate redshift MUSE sample (z ∼ 0.5). Whilst there is, at most, a weak trend between velocity dispersion and stellar mass, at fixed mass there is a strong increase with redshift. At all redshifts, galaxies appear to follow the same weak trend of increasing velocity dispersion with star formation rate. Our results are consistent with an evolution of galaxy dynamics driven by discs that are more gas rich, and increasingly gravitationally unstable, as a function of increasing redshift. Finally, we test two analytic models that predict turbulence is driven by either gravitational instabilities or stellar feedback. Both provide an adequate description of the data, and further observations are required to rule out either model.

Citation

Johnson, H., Harrison, C., Swinbank, A., Tiley, A., Stott, J., Bower, R., …Richards, S. (2018). The KMOS Redshift One Spectroscopic Survey (KROSS): the origin of disc turbulence in z ≈ 1 star-forming galaxies. Monthly Notices of the Royal Astronomical Society, 474(4), 5076-5104. https://doi.org/10.1093/mnras/stx3016

Journal Article Type Article
Acceptance Date Nov 21, 2017
Online Publication Date Nov 23, 2017
Publication Date Mar 11, 2018
Deposit Date Jan 16, 2018
Publicly Available Date Mar 29, 2024
Journal Monthly Notices of the Royal Astronomical Society
Print ISSN 0035-8711
Electronic ISSN 1365-2966
Publisher Royal Astronomical Society
Peer Reviewed Peer Reviewed
Volume 474
Issue 4
Pages 5076-5104
DOI https://doi.org/10.1093/mnras/stx3016

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Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2017 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.





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