When the wave hits: star forming lenticular galaxies within the Fornax cluster

CORTESI, A.; REIS LOPES, A.; DIMAURO, P.; SMITH CASTELLI, A.; ET AL.

Workshop; 16th S-PLUS Collaboration Meeting; 2021

Lenticular galaxies lie at the apex of the Hubble tuning fork between E and S, given their hybrid structure, which contains a disk, as S galaxies, but without spiral arms, as for E galaxies.The number of lenticular galaxies is found to increase toward the center of clusters of galaxies, while the number of S follows the opposite trend. A similar trend is found with redshift, where the number of lenticular galaxies increases with decreasing redshift, at the expenses of the number of S galaxies. Based on these facts it has been hypothesized that S galaxies are the progenitor of S0 galaxies, being their gas removed through mechanisms dictated by the environment (stripping, harassment), or internal mechanisms such as AGN feedback, and finally minor and major mergers. At the low redshift universe, lenticular galaxies account for more than 50% of the total number of massive galaxies. Recently, it has been claimed that S0s are formed through different mechanisms, mostly connected to their mass. Yet the role of the environment in their formation, especially the role of preprocessing before entering the cluster environment, as well as the driving mechanisms of formation of S0s within the cluster are still unclear. In this poster, we present a pilot study of lenticular galaxies in the Fornax cluster, making use of the large coverage of the S-PLUS data, which allows studying the effects of the environment at large radii from the cluster center. Moreover, by using the esquiseute S-PLUS filter system, we found that the majority of these S0 galaxies show evidence of emission lines (i.e. present recent star formation activity in small clumps) - an extraordinary discovery given that these types of galaxies are expected to be passive.