The KMOS Redshift One Spectroscopic Survey (KROSS):dynamical properties, gas and dark matter fractions of typical z~1 star-forming galaxies
By J. Stott, A. M. Swinbank, H. Johnson, A. Tiley, G. Magdis, Richard G. Bower, A. Bunker, M. Bureau, C. Harrison, M. Jarvis and 5 more. 2016
150 citations recorded by the source corpus.
The KMOS Redshift One Spectroscopic Survey (KROSS) is an ESO guaranteed time survey of 795 typical star-forming galaxies in the redshift range z=0.8-1.0 with the KMOS instrument on the VLT. In this paper we present resolved kinematics and star formation rates for 584 z~1 galaxies. This constitutes the largest near-infrared Integral Field Unit survey of galaxies at z~1 to date. We demonstrate the success of our selection criteria with 90% of our targets found to be Halpha emitters, of which 81% are spatially resolved. The fraction of the resolved KROSS sample with dynamics dominated by ordered rotation is found to be 83$\pm$5%. However, when compared with local samples these are turbulent discs with high gas to baryonic mass fractions, ~35%, and the majority are consistent with being marginally unstable (Toomre Q~1). There is no strong correlation between galaxy averaged velocity dispersion and the total star formation rate, suggesting that feedback from star formation is not the origin of the elevated turbulence. We postulate that it is the ubiquity of high (likely molecular) gas fractions and the associated gravitational instabilities that drive the elevated star-formation rates in these typical z~1 galaxies, leading to the ten-fold enhanced star-formation rate density. Finally, by comparing the gas masses obtained from inverting the star-formation law with the dynamical and stellar masses, we infer an average dark matter to total mass fraction within 2.2$r_e$ (9.5kpc) of 65$\pm$12%, in agreement with the results from hydrodynamic simulations of galaxy formation.
Subfields: Astronomy and Astrophysics
View Paper: https://www.semanticscholar.org/paper/7db436227e04146d318b813fc069e76b0fd32881
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In Astronomy and Astrophysics
Citations in the corpus
- The SINS/zC-SINF Survey of z ∼ 2 Galaxy Kinematics: SINFONI Adaptive Optics–assisted Data and Kiloparsec-scale Emission-line Properties (2018, unknown): “…al. 2009; Wright et al. 2009; Épinat et al. 2009, 2012; Jones et al. 2010b; Mancini et al. 2011; Gnerucci et al. 2011a,b; Wisnioski et al. 2011, 2012, 2015; Swinbank et al. 2012b,a; Newman et al. 2013; Buitrago et al. 2014; Stott et al. 2014, 2016; Leethochawalit et al. 2016; Molina et al. 2017).”
- Structure and Kinematics of Early-Type Galaxies from Integral Field Spectroscopy (2016, background): “Only the line emission from the gas-rich star-forming galaxies can be currently spatially resolved with IFS at significant redshift (e.g. Wisnioski et al. 2015; Stott et al. 2016).”
- A unified model for galactic discs: star formation, turbulence driving, and mass transport (2017, methodology): “The KMOS Redshift One Spectroscopic Survey (KROSS; Stott et al. 2016) is a spectroscopic survey of redshift one galaxies using KMOS on the VLT. Johnson et al. (2017) provides measurements of velocity dispersion based on the H α line in 472 galaxies from the survey, along with star formation rates…”
- The Universe Is Reionizing at z ∼ 7: Bayesian Inference of the IGM Neutral Fraction Using Lyα Emission from Galaxies (2017, background): “…probably reside in halos with mass ∼> 1011M , which may already have stable gaseous disks, as suggested by recent ALMA observations of two UV bright galaxies at z ∼ 6 (Smit et al. 2018) and observations of stable rotation in low mass galaxies at z ∼ 1 − 2 (Stott et al. 2016; Mason et al. 2016).”
- Inferences on the timeline of reionization at z ∼ 8 from the KMOS Lens-Amplified Spectroscopic Survey (2019, methodology): “Similar techniques to improve sky subtraction are described by Stott et al. (2016).”