The KMOS Redshift One Spectroscopic Survey (KROSS):the origin of disc turbulence in z~0.9 star-forming galaxies

Johnson, H. L. and Harrison, C. M. and Swinbank, A. M. and Tiley, A. L. and Stott, J. P. and Bower, R. G. and Smail, Ian and Bunker, A. J. and Sobral, D. and Turner, O. J. and Best, P. and Bureau, M. and Cirasuolo, M. and Jarvis, M. J. and Magdis, G. and Sharples, R. M. and Bland-Hawthorn, J. and Catinella, B. and Cortese, L. and Croom, S. M. and Federrath, C. and Glazebrook, K. and Sweet, S. M. and Bryant, J. J. and Goodwin, M. and Konstantopoulos, I. S. and Lawrence, J. S. and Medling, A. M. and Owers, M. S. and Richards, S. (2018) The KMOS Redshift One Spectroscopic Survey (KROSS):the origin of disc turbulence in z~0.9 star-forming galaxies. Monthly Notices of the Royal Astronomical Society, 474 (4). pp. 5076-5104. ISSN 0035-8711

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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% with v_C/sigma_0 > 1) but also dynamically hot and highly turbulent. After correcting for beam smearing effects, the median intrinsic velocity dispersion for the final sample is sigma_0 = 43.2 +/- 0.8 km/s with a rotational velocity to dispersion ratio of v_C/sigma_0 = 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). While 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 disks 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.

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Journal Article
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Monthly Notices of the Royal Astronomical Society
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This is a pre-copy-editing, author-produced PDF of an article accepted for publication in Monthly Notices of the Royal Astronomical Society following peer review. The definitive publisher-authenticated version H L Johnson, C M Harrison, A M Swinbank, A L Tiley, J P Stott, R G Bower, Ian Smail, A J Bunker, D Sobral, O J Turner, P Best, M Bureau, M Cirasuolo, M J Jarvis, G Magdis, R M Sharples, 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; 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, Volume 474, Issue 4, 11 March 2018, Pages 5076–5104, is available online at: Data available at
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21 Nov 2017 20:01
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25 Oct 2020 04:58