Oral Presentation

Why is there star rebirth inside galaxies? An investigation into the Rejuvenated Galaxies (RGs) from MaNGA.

Author(s): Ting-Xuan Li (Institute of Astrophysics, NTU)

Presenter: Ting-Xuan Li (National Taiwan University)

Galaxies generally evolve from active to passive, which analog to high star-formation rate (SFR) to low SFR. However, some galaxies were observed to evolve from low SFR to high SFR. Our main motivation is to investigate the origin of the rejuvenated gas through gas-phase metallicity. A lower gas-phase metallicity value is anticipated if the rejuvenated gas originates from the intergalactic space. We totally identify 27 and 11 RGs from spatially-resolved and integrated selection methods, respectively, from approximately 10,000 MaNGA galaxies. We found that the gas-phase metallicity of rejuvenated spaxels is not significantly lower than normal star-forming spaxels; therefore, there is not strong evidence to suggest that the gas comes from intergalactic space. Additional analyses are ongoing and will be presented upon completion.