The SAMI galaxy survey: gas velocity dispersions in low-z star-forming galaxies and the drivers of turbulence

• Published in: Monthly Notices of the Royal Astronomical Society
• Main 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.
• Other Authors: Swinburne University of Technology
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Oxford University Press (OUP) 2020
• Subjects: sami
• Online Access: http://hdl.handle.net/1959.3/456557; https://doi.org/10.1093/mnras/staa1272

We infer the intrinsic ionized gas kinematics for 383 star-forming galaxies across a range of integrated star formation rates (SFR is an element of [10(-3), 10(2)] M-circle dot yr(-1)) at z less than or similar to 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 (sigma(v,z)) to be positively correlated with measures of SFR, stellar mass, HI gas mass, and rotational velocity. The greatest correlation is with SFR surface density (Sigma(SFR)). Using the total sample, we find sigma(v,z) increases slowly as a function of integrated SFR in the range SFR is an element of [10(-3), 1] M-circle dot yr(-1) from 17 +/- 3 to 24 +/- 5 kms(-1) followed by a steeper increase up to sigma(v,z) similar to 80 km s(-1) for SFR greater than or similar to 1M(circle dot) yr(-1). This is consistent with recent theoretical models that suggest a sv, z floor driven by star formation feedback processes with an upturn in sv, z at higher SFR driven by gravitational transport of gas through the disc.