The SAMI galaxy survey: gas velocity dispersions in low-z star-forming galaxies and the drivers of turbulence. Issue 2 (20th May 2020)

• Record Type: Journal Article
• Authors: Varidel, Mathew R; Croom, Scott M; Lewis, Geraint F; Fisher, Deanne B; Glazebrook, Karl; Catinella, Barbara; Cortese, Luca; Krumholz, Mark R; Bland-Hawthorn, Joss; Bryant, Julia J; Groves, Brent; Brough, Sarah; Federrath, Christoph; Lawrence, Jon S; Lorente, Nuria P; Owers, Matt S; Richards, Samuel N; López-Sánchez, Ángel R; Sweet, Sarah M; van de Sande, Jesse; Vaughan, Sam P
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 495:Issue 2(2020)
• Page Start: 2265
• Page End: 2284
• Publication Date: 2020-05-20
• Subjects: methods: data analysis -- methods: statistical -- techniques: imaging spectroscopy -- galaxies: disc; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/staa1272
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We infer the intrinsic ionized gas kinematics for 383 star-forming galaxies across a range of integrated star formation rates (SFR ∈ [10 −3, 10 2 ] M⊙ yr −1 ) at z ≲ 0.1 using a consistent 3D forward-modelling technique. The total sample is a combination of galaxies from the Sydney-AAO Multiobject Integral field Spectrograph (SAMI) Galaxy survey and DYnamics of Newly Assembled Massive Objects survey. For typical low- z galaxies taken from the SAMI Galaxy Survey, we find the vertical velocity dispersion (σ v, z ) to be positively correlated with measures of SFR, stellar mass, H i gas mass, and rotational velocity. The greatest correlation is with SFR surface density (ΣSFR ). Using the total sample, we find σ v, z increases slowly as a function of integrated SFR in the range SFR ∈ [10 −3, 1] M⊙ yr −1 from 17 ± 3 to 24 ± 5 km s −1 followed by a steeper increase up to σ v, z ∼80 km s −1 for SFR ≳ 1 M⊙ yr −1 . This is consistent with recent theoretical models that suggest a σ v, z floor driven by star formation feedback processes with an upturn in σ v, z at higher SFR driven by gravitational transport of gas through the disc.