The DUVET Survey: Resolved Maps of Star Formation Driven Outflows in a Compact, Starbursting Disk Galaxy

TL;DR

This study uses spatially resolved measurements to map star formation driven outflows in a nearby starburst galaxy, revealing high outflow covering fractions and relationships consistent with energy-driven feedback models.

Contribution

Develops a new multi-step method for identifying and decomposing outflows in spatially resolved galaxy data, providing detailed outflow maps and analysis.

Findings

Outflows detected in nearly all regions within the galaxy's half-light radius.

Outflow velocities range from 100 to 600 km/s, correlated with star formation rate surface density.

Results support energy-driven feedback models over momentum-driven winds.

Abstract

We study star formation driven outflows in a $z\sim0.02$ starbursting disk galaxy, IRAS08339+6517, using spatially resolved measurements from the Keck Cosmic Web Imager (KCWI). We develop a new method incorporating a multi-step process to determine whether an outflow should be fit in each spaxel, and then subsequently decompose the emission line into multiple components. We detect outflows ranging in velocity, $v_{\rm out}$, from $100-600$ km s$^{-1}$ across a range of star formation rate surface densities, $\Sigma_{\rm SFR}$, from $\sim$0.01-10 M$_\odot$ yr$^{-1}$ kpc$^{-2}$ in resolution elements of a few hundred parsec. Outflows are detected in $\sim100\%$ of all spaxels within the half-light radius, and $\sim70\%$ within $r_{90}$, suggestive of a high covering fraction for this starbursting disk galaxy. Around $2/3$ of the total outflowing mass originates from the star forming ring, which corresponds to $<10\%$ of the total area of the galaxy. We find that the relationship between $v_{\rm out}$ and the $\Sigma_{\rm SFR}$, as well as between the mass loading factor, $\eta$, and the $\Sigma_{\rm SFR}$, are consistent with trends expected from energy-driven feedback models. We study the resolution effects on this relationship and find stronger correlations above a re-binned size-scale of $\sim500$ pc. Conversely, we do not find statistically significant consistency with the prediction from momentum-driven winds.