Star-Forming S0 Galaxies in SDSS-IV MaNGA Survey

TL;DR

This study investigates star-forming S0 galaxies in the SDSS-IV MaNGA survey, revealing their smaller stellar masses, pseudo bulges, environmental effects on spin, and evidence of metal-poor gas accretion, highlighting their unique evolutionary processes.

Contribution

It provides a detailed analysis of the properties and environmental influences on star-forming S0 galaxies, introducing new insights into their bulge structure and gas accretion processes.

Findings

SFS0s have smaller stellar masses than normal S0s.

SFS0s possess pseudo bulges indicated by lower Sersic indices.

Field SFS0s show nitrogen enrichment, suggesting metal-poor gas accretion.

Abstract

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.