Presentation #341.08 in the session “Galaxy Quenching”.
E+A galaxies are a type of post-starburst galaxy that experience rapid and complete quenching around 1 Gyr, and are an invaluable phase for understanding how galaxies evolve. Members of the Y/Dim Collaboration identified more than 400 E+A galaxy candidates in nearby clusters using single-fiber spectra from Sloan Digital Sky Survey (SDSS) Data Release 16. Within this sample, at least 29 E+A galaxy candidates were also observed by the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) Survey, which released spatially resolved observations of 4,621 unique galaxies from the first three years of the survey in DR16. For 29 E+A galaxy candidates in the Coma Cluster, we map spectral features from SDSS-MaNGA observations, including using the equivalent width of Hα and the line ratio of [NII]/Hα to classify the dominant ionization source for each spaxel. These maps demonstrate that each candidate is quenched throughout the entirety of the galaxy and have primarily passively aging stellar populations, with significant ionization from hot evolved stars. While mergers are thought to be one major mechanism of both inciting the starburst phase and exhausting gas reservoirs, the majority of these E+A galaxy candidates demonstrate coherent kinematic rotation. These galaxies may establish an important link between a pure E+A phase and the “red sequence” of quiescence. This work was supported by the Alfred P. Sloan Foundation via the SDSS-IV Faculty and Student Team (FaST) initiative, ARC Agreement SSP483, and by NSF grants AST-1852355, 1852360, 1460939, and 1460860 to the American Museum of Natural History and CUNY College of Staten Island.