2019MNRAS.482.4032L

We present a sample of 17 objects from the CALIFA survey where we find initial evidence of galactic winds based on their off-axis ionization properties. We identify the presence of outflows using various optical diagnostic diagrams [e.g. EW(H α), [N II]/H α, [S II]/H α, [O I]/H α line-ratio maps]. We find that all 17 candidate outflow galaxies lie along the sequence of active star formation in the M_* versus star-formation rate (SFR) diagram, without a clear excess in the integrated SFR. The location of galaxies along the star-formation main sequence does not influence strongly the presence or not of outflows. The analysis of the SFR density (Σ_SFR) reveals that the CALIFA sources present higher values when compared with normal star-forming galaxies. The strength of this relation depends on the calibrator used to estimate the SFR. This excess in Σ_SFR is significant within the first effective radius supporting the idea that most outflows are driven by processes in the inner regions of a galaxy. We find that the molecular gas mass density (Σ_gas) is a key parameter that plays an important role in the generation of outflows through its association with the local SFR. The canonical threshold reported for the generation of outflows - Σ_SFR > 0.1 M_☉yr^–1 kpc^–2 - is only marginally exceeded in our sample. Within the Kennicutt-Schmidt diagram we propose a domain for galaxies hosting starburst-driven outflows defined by Σ_ SFR_> 10^–2 M_☉yr^–1 kpc^–2 and Σ_gas> 10^1.2 M_☉pc^–2 within a central kiloparsec region.