Optically Passive Infall Spirals In Stages: Star Formation Only Semi-quenched
Wolf, Christian; Gray, M. E.; Bell, E. F.;Gallazzi, A.; Meisenheimer, K.; Papovich, C.;Aragon-Salamanca, A.; Bacon, D.; Balogh, M.;Barraza, F. D.; Barden, M.; Boehm, A.;Caldwell, J. A. R.; Haeussler, B.; Heymans, C.;Jahnke, K.; Jogee, S.; van Kampen, E.; Koposov, S.;Lane, K.; McIntosh, D. H.; Peng, C.; Rix, H.;Sanchez, S. F.; Somerville, R. S.; Taylor, A. N.;Wisotzki, L.; Zheng, X.. Optically Passive Infall Spirals In Stages: Star Formation Only Semi-quenched. American Astronomical Society, AAS Meeting #211, #67.01; Bulletin of the American Astronomical Society. 2007, Vol. Vol. 39, p.856, p. -2007.
. In contrast, new data from Spitzer/MIPS show that these are indeed star-forming galaxies with the highest obscuration levels found in the cluster. At fixed mass their star formation rates are only about 3 times lower than those of regular blue galaxies. Hence, we conclude that these are galaxies caught in the act of transformation with their star formation being only partially suppressed. It is possible that optically passive spirals falling into clusters are generally still forming stars, and their further study could reveal the timescales of star formation quenching by the cluster environment. We acknowledge support from NASA HST grant GO-10395.
. In contrast, new data from Spitzer/MIPS show that these are indeed star-forming galaxies with the highest obscuration levels found in the cluster. At fixed mass their star formation rates are only about 3 times lower than those of regular blue galaxies. Hence, we conclude that these are galaxies caught in the act of transformation with their star formation being only partially suppressed. It is possible that optically passive spirals falling into clusters are generally still forming stars, and their further study could reveal the timescales of star formation quenching by the cluster environment. We acknowledge support from NASA HST grant GO-10395.