Presentation #341.11 in the session “Galaxy Quenching”.
E+A galaxies are post-starburst galaxies that have recently undergone complete quenching of their star formation, making them a valuable source for studying the evolution of galaxies and their environments. From the Y/Dim Collaboration sample of E+A galaxies (401 of which are in four nearby clusters, with more identified in comparison fields and background regions) across 16 fields totaling roughly 480 square degrees, we have visually and spectroscopically identified 17 E+A galaxies and 16 companion galaxies that are strong candidates for merger activities. 10 E+As making up 9 different interacting groups are in, or in the vicinity of, the nearby Coma, Hercules, Leo, and Virgo clusters of galaxies, and the remainder are galaxies in the field. We have followed the redshift criteria of Yamauchi, Yagi and Goto (2008, MNRAS, 390, 1) and ensured that all our E+As and companions both have redshift data and are within z=0.002 of each other. In addition to inspecting the galaxies within each pair, we are investigating patterns between the 17 E+As and the 16 companions; these comparisons will give insight into how merging activity affects E+A formation and quenching efficiency. 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.