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تسجيل مستخدم جديدThe SAMI Galaxy Survey: Gas velocity dispersions in low-$z$ star-forming galaxies and the drivers of turbulence
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We infer the intrinsic ionised gas kinematics for 383 star-forming galaxies across a range of integrated star-formation rates (SFR $in [10^{-3}, 10^2]$ M$_odot$ yr$^{-1}$) at $z lesssim 0.1$ using a consistent 3D forward-modelling technique. The total sample is a combination of galaxies from the SAMI Galaxy Survey and DYNAMO 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 star-formation rate, stellar mass, HI gas mass, and rotational velocity. The greatest correlation is with star-formation rate surface density ($Sigma_text{SFR}$). Using the total sample, we find $sigma_{v, z}$ increases slowly as a function of integrated star-formation rate in the range SFR $in$ [$10^{-3}$, 1] M$_odot$ yr$^{-1}$ from $17pm3$ km s$^{-1}$ to $24pm5$ km s$^{-1}$ followed by a steeper increase up to $sigma_{v, z}$ $sim 80$ km s$^{-1}$ for SFR $gtrsim 1$ M$_odot$ yr$^{-1}$. This is consistent with recent theoretical models that suggest a $sigma_{v, z}$ floor driven by star-formation feedback processes with an upturn in $sigma_{v, z}$ at higher SFR driven by gravitational transport of gas through the disc.
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