Zhen-Kai Gao (NCU); Chorng-Yuan Hwang (NCU)
Most of the early-type galaxies (ETGs) are thought to be red and passive, while previous studies found some blue ETGs now experiencing star formation. Those ETGs with star formation usually have characteristics of low mass and being in the low-density environment. Due to the lack of neighbors in normal size, the major merger could hardly contribute to these star formation event. Minor merger and cold accretion are thus the two main origins of the gas reservoir inside the star-forming ETGs. To trace the origin of the material for star formation, we adopted the observations from SDSS MaNGA integral field spectroscopy (IFS) to investigate where the gas came from, how the newly coming gas interacts with the host galaxies, and after these, where the new-born stars reside.