SDSS IV MaNGA -- Star-Formation Driven Biconical Outflows in Face-On Galaxies

TL;DR

This study identifies and characterizes star-formation driven biconical gas outflows in face-on galaxies using SDSS MaNGA data, revealing their properties, origins, and relation to galaxy interactions.

Contribution

It provides the first detailed analysis of FSFB outflows in face-on galaxies, linking outflows to galaxy interactions and gas replenishment mechanisms.

Findings

132 face-on galaxies with outflows identified

Outflow velocities up to 212 km/s observed

Outflows linked to galaxy interactions and gas accretion

Abstract

We find 132 face-on and low inclination galaxies with central star formation driven biconical gas outflows (FSFB) in the SDSS MaNGA (Mapping Nearby Galaxies at APO) survey. The FSFB galaxies show either double peaked or broadened emission line profiles at their centres. The peak and maximum outflow velocities are 58 and 212 km/s, respectively. The gas velocity dispersion reveals a mild dependence on the central star formation surface density compatible with models of gas dispersion powered by the Jeans instability in gas clumps or by gas turbulence dissipation. We estimate the gas outflow rate and conclude that the central gas depletion time does not depend on galactic mass. In turn, the ratio of the gas outflow rate to the gas consumption rate by the star formation is low in massive galaxies and high in low-mass objects, while the star formation is a more rapid process of the gas consumption. We compare properties of the FSFB galaxies with a control sample of 375 comparison galaxies and find that the FSFB objects have high central concentration of star formation, and also younger central stellar population with respect to their periphery. We analysed the environment of the galaxies and identified nearby satellites and elements of low surface brightness structure. We see that many tidal-enhanced features that can be assigned to early and intermediate stages of galactic interaction are much more frequent in the FSFB galaxies with respect to the comparison sample. We conclude that the gas should be replenished via the accretion from small satellites.