Spatially resolved signature of quenching in star-forming galaxies
  Understanding when, how and where star formation ceased (quenching) within
galaxies is still a critical subject in galaxy evolution studies. Taking
advantage of the new methodology developed by Quai et al. (2018) to select
recently quenched galaxies, we explored the spatial information provided by IFU
data to get critical insights on this process. In particular, we analyse 10
SDSS-IV MaNGA galaxies that show regions with low [O III]/H{\alpha} compatible
with a recent quenching of the star formation. We compare the properties of
these 10 galaxies with those of a control sample of 8 MaNGA galaxies with
ongoing star formation in the same stellar mass, redshift and gas-phase
metallicity range. The quenching regions found are located between 0.5 and 1.1
effective radii from the centre. This result is supported by the analysis of
the average radial profile of the ionisation parameter, which reaches a minimum
at the same radii, while the one of the star-forming sample shows an almost
flat trend. These quenching regions occupy a total area between 15\% and 45\%
of our galaxies. Moreover, the average radial profile of the star formation
rate surface density of our sample is lower and flatter than that of the
control sample, at any radii, suggesting a systematic suppression of the star
formation in the inner part of our galaxies. Finally, the radial profile of
gas-phase metallicity of the two samples have a similar slope and
normalisation. Our results cannot be ascribed to a difference in the intrinsic
properties of the analysed galaxies, suggesting a quenching scenario more
complicated than a simple inside-out quenching.
