Post-Starburst Galaxies in SDSS-IV MaNGA
  Post-starburst galaxies, identified by their unusually strong Balmer
absorption lines and weaker than average emission lines, have traditionally
been selected based on their central stellar populations. Here we identify 360
galaxies with post-starburst regions from the MaNGA integral field survey and
classify these galaxies into three types: 31 galaxies with central
post-starburst regions (CPSB), 37 galaxies with off-center ring-like
post-starburst regions (RPSB) and 292 galaxies with irregular post-starburst
regions (IPSB). Focussing on the CPSB and RPSB samples, and comparing their
radial gradients in D$_n$4000, H$\delta_{\rm A}$ and W(H$\alpha$) to control
samples, we find that while the CPSBs have suppressed star formation throughout
their bulge and disk, and clear evidence of rapid decline of star formation in
the central regions, the RPSBs only show clear evidence of recently rapidly
suppressed star formation in their outer regions and an ongoing central
starburst. The radial profiles in mass-weighted age and stellar $v/\sigma$
indicate that CPSBs and RPSBs are not simply different evolutionary stages of
the same event, rather that CPSB galaxies are caused by a significant
disruptive event, while RPSB galaxies are caused by disruption of gas fuelling
to the outer regions. Compared to the control samples, both CPSB and RPSB
galaxies show a higher fraction of interactions/mergers, misaligned gas or bars
that might be the cause of the gas inflows and subsequent quenching.
