J/MNRAS/474/5076 KMOS Redshift One Spectroscopic Survey (Johnson+, 2018)
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.
<Mon. Not. R. Astron. Soc., 474, 5076-5104 (2018)>
=2018MNRAS.474.5076J 2018MNRAS.474.5076J (SIMBAD/NED BibCode)
ADC_Keywords: Galaxy catalogs ; Redshifts ; Velocity dispersion
Keywords: galaxies: evolution - galaxies: high-redshift -
galaxies: kinematics and dynamics - infrared: galaxies
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±0.8km/s 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.
Description:
In this work, we have analysed the velocity dispersion properties of
472 Hα-detected star-forming galaxies observed as part of
KROSS (Stott et al.. 2016MNRAS.457.1888S 2016MNRAS.457.1888S; Harrison et al.,
2017MNRAS.467.1965H 2017MNRAS.467.1965H, Cat. J/MNRAS/467/1965).
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 96 472 Intrinsic velocity dispersion and related quantities
--------------------------------------------------------------------------------
See also:
J/MNRAS/467/1965 : KMOS Redshift One Spectroscopic Survey (Harrison+, 2017)
http://astro.dur.ac.uk/KROSS : KROSS Home Page
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 28 A28 --- Name Name
30- 31 I2 h RAh Right ascension (J2000)
33- 34 I2 min RAm Right ascension (J2000)
36- 39 F4.1 s RAs Right ascension (J2000)
41 A1 --- DE- Declination sign (J2000)
42- 43 I2 deg DEd Declination (J2000)
45- 46 I2 arcmin DEm Declination (J2000)
48- 49 I2 arcsec DEs Declination (J2000)
51- 56 F6.4 --- z Redshift
58- 60 I3 km/s sigma0obs Observed corrected velocity dispersion
62- 64 I3 km/s e_sigma0obs rms uncertainty on sigma0obs
66- 68 I3 km/s sigma0 Beam smearing corrected velocity dispersion
70- 71 I2 km/s e_sigma0 rms uncertainty on sigma0
73 A1 --- Flag [MO] Flag (1)
75- 77 F3.1 --- Rd/RPSF Ratio between the disc radius (in arcsec)
and half of the seeing FWHM
79- 81 F3.1 --- e_Rd/RPSF rms uncertainty on Rd/RPSF
83- 86 F4.1 --- Qg Global Toomre Qg parameter (2)
88- 91 F4.1 --- E_Qg Error on Qg (upper value)
93- 96 F4.1 --- e_Qg Error on Qg (lower value)
--------------------------------------------------------------------------------
Note (1): Flag as follows:
O = dispersion measured in the outskirts of the disk
M = dispersion measured from the median of all available pixels
Note (2): global Toomre Qg parameter for each galaxy, derived by inverting
the Kennicutt-Schmidt relation to estimate Σgas.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 11-Mar-2021