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

Abstract

We measure resolved (kiloparsec-scale) outflow properties in a sample of 10 starburst galaxies from the DUVET (Deep near-UV observations of Entrained gas in Turbulent galaxies) sample, using Keck/KCWI observations of H${\hat{I}}^2$ and [OIII]~$\hat{I}»$5007. We measure $\sim 460$ lines-of-sight that contain outflows, and use these to study scaling relationships of outflow velocity ($v_{\mathrm{out}}$), mass-loading factor ($\hat{I}\cdot$; mass outflow rate per SFR) and mass flux ($\dot{\hat{I}}{\pounds }_{\mathrm{out}}$; mass outflow rate per area) with co-located SFR surface density ($\hat{I}{\pounds }_{\mathrm{SFR}}$) and stellar mass surface density ($\hat{I}{\pounds }_{\ast }$). We find strong, positive correlations of $\dot{\hat{I}}{\pounds }_{\mathrm{out}}\propto \hat{I}{\pounds }_{\mathrm{SFR}}^{1.2}$ and $\dot{\hat{I}}{\pounds }_{\mathrm{out}}\propto \hat{I}{\pounds }_{\ast }^{1.5}$. We also find shallow correlations between $v_{\mathrm{out}}$ and both $\hat{I}{\pounds }_{\mathrm{SFR}}$ and $\hat{I}{\pounds }_{\ast }$. Our resolved observations do not suggest a threshold in outflows with $\hat{I}{\pounds }_{\mathrm{SFR}}$, but rather we find that the local specific SFR ($\hat{I}{\pounds }_{\mathrm{SFR}}/\hat{I}{\pounds }_{\ast }$) is a better predictor of where outflows are detected. We find that outflows are very common above $\hat{I}{\pounds }_{\mathrm{SFR}}/\hat{I}{\pounds }_{\ast }\gtrsim 0.1$~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.

23 pages, 9 figures, plus 5 figures in the Appendix. Supplementary table of results in Ancillary Files. Resubmitted to MNRAS after referee report