Properties of ionized outflows in MaNGA DR2 galaxies
  We present the results from a systematic search and characterization of
ionized outflows in nearby galaxies using the data from the second Data Release
of the MaNGA Survey (DR2; > 2700 galaxies, z < 0.015). Using the
spatially-resolved spectral information provided by the MANGA data, we have
identified ~5200 Halpha-emitting regions across the galaxies and searched for
signatures of ionized outflows. We find evidence for ionized outflows in 105
regions from 103 galaxies, roughly 7% of all the Halpha-emitting galaxies
identified in this work. Our analysis allows us to study ionized outflows in
individual regions with SFRs down to ~0.01 Msun yr-1, extending the ranges
probed by previous works. The kinematics of the outflowing gas are strongly
linked to the type of ionization mechanism: regions characterized by LIER
emission host outflows with more extreme kinematics (FWHM_broad ~900 km/s),
followed by those originated in AGN (~550 km/s), `Intermediate' (~450 km/s) and
SF (~350 km/s) regions. Moreover, in most of the outflows we find evidence for
gas ionized by shocks. We find a trend for higher outflow kinematics towards
larger stellar masses of the host galaxies but no significant variation as a
function of star formation. The fraction of outflowing gas that can escape from
galaxies decreases towards higher dynamical masses, contributing to the
preservation of the mass-metallicity relation by regulating the amount of
metals in galaxies. Finally, assuming that the extensions of the outflows are
significantly larger than the individual star-forming regions, as found in
previous works, our results also support the presence of star formation within
ionized outflows, as recently reported by Maiolino et al. 2017 and Gallagher et
al. 2019.
