Star-Forming S0 Galaxies in SDSS-IV MaNGA Survey
  To investigate star-forming activities in early-type galaxies, we select a
sample of 52 star-forming S0 galaxies (SFS0s) from the SDSS-IV MaNGA survey. We
find that SFS0s have smaller stellar mass compared to normal S0s in MaNGA.
After matching the stellar mass to select the control sample, we find that the
mean S\'{e}rsic index of SFS0s' bulges (1.76$\pm$0.21) is significantly smaller
than that of the control sample (2.57$\pm$0.20), suggesting the existence of a
pseudo bulge in SFS0s. After introducing the environmental information, SFS0s
show smaller spin parameters in the field than in groups, while the control
sample has no obvious difference in different environments, which may suggest
different dynamical processes in SFS0s. Furthermore, with derived N/O and O/H
abundance ratios, SFS0s in the field show nitrogen enrichment, providing
evidence for the accretion of metal-poor gas in the field environment. To study
the star formation relation, we show that the slope of the spatially resolved
star formation main sequence is nearly 1.0 with MaNGA IFU data, confirming the
self-regulation of star formation activities at the kpc scales.
