DUVET: sub-kiloparsec resolved star formation driven outflows in a sample of local starbursting disc galaxies

Abstract

ABSTRACT We measure resolved (kiloparsec-scale) outflow properties in a sample of 10 starburst galaxies from the Deep near-UV observations of Entrained gas in Turbulent (DUVET) galaxies sample, using Keck/KCWI observations of H $\beta$ and [O iii] $\lambda$5007. We measure $\sim 460$ lines of sight that contain outflows, and use these to study scaling relationships of outflow velocity ($v_{\rm out}$), mass-loading factor ($\eta$; mass outflow rate per star formation rate) and mass flux ($\dot{\Sigma }_{\rm out}$; mass outflow rate per area) with co-located star formation rate surface density ($\Sigma _{\rm SFR}$) and stellar mass surface density ($\Sigma _{\ast }$). We find strong, positive correlations of $\dot{\Sigma }_{\rm out} \propto \Sigma _{\rm SFR}^{1.2}$ and $\dot{\Sigma }_{\rm out} \propto \Sigma _{\ast }^{1.5}$. We also find shallow correlations between $v_{\rm out}$ and both $\Sigma _{\rm SFR}$ and $\Sigma _{\ast }$. Our resolved observations do not suggest a threshold in outflows with $\Sigma _{\rm SFR}$, but rather we find that the local specific star formation rate ($\Sigma _{\rm SFR}/\Sigma _\ast$) is a better predictor of where outflows are detected. We find that outflows are very common above $\Sigma _{\rm SFR}/\Sigma _\ast \gtrsim 0.1$ Gyr$^{-1}$ and rare below this value. We argue that our results are consistent with a picture in which outflows are driven by supernovae, and require more significant injected energy in higher mass surface density environments to overcome local gravity. The correlations we present here provide a statistically robust, direct comparison for simulations and higher redshift results from JWST.

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