Two-Face(s): ionized and neutral gas winds in the local Universe

Understand

We present a comprehensive study of the Na I $\lambda$5890, 5895 (Na I D) resonant lines in the Sloan Digital Sky Survey (SDSS, DR7) spectroscopic sample to look for neutral gas outflows in the local galaxies.

• Individual galaxy spectra are stacked in bins of M${\star}$ and SFR to investigate the dependence of galactic wind occurrence and velocity as a function of the galaxy position in the SFR-$M{\star}$ plane.
• In massive galaxies at the high SFR tail we find evidence of a significant blue-shifted Na I D absorption, which we interpret as evidence of neutral outflowing gas.
• The occurrence of the blue-shifted absorption is observed at the same significance for purely SF galaxies, AGN and composite systems at fixed SFR.