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UV Imaging of the Galaxy Cluster CL0939+4713 (Abell 851) at z=0.41

Lucio M. Buson·Francesco Bertola·Michele Cappellari·Cesare Chiosi·Alan Dressler·Augustus Oemler Jr
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Abstract

The first UV F300W and F218W WFPC2 observations of the rich galaxy cluster CL0939+4713 at z=0.41 are presented and discussed. UV/optical two-color and c-m diagrams of the sources detected in the F300W waveband are constructed. Thanks to pre-existing HST optical images of the same field a morphological classification for the majority of these objects is also provided. Moreover, taking advantage of recent redshift surveys along CL0939+4713 line of sight, separate diagrams comparing the properties of galaxies belonging to the cluster and to its close projected field are presented. Possible evolutionary effects in the UV from z~0.4 to present time are investigated by comparing the restframe [mid-UV-Optical] colors of galaxies in CL0939+4713 with balloon-borne data of the Coma cluster, as well as by resorting to suitable galaxy evolution models. Finally, current attempts to constrain the epoch of the UV-upturn onset in evolved populations by means of HST UV observations are discussed.

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Lucio M. Buson, Francesco Bertola, Michele Cappellari, Cesare Chiosi, Alan Dressler, Augustus Oemler Jr. 1999-10-05. UV Imaging of the Galaxy Cluster CL0939+4713 (Abell 851) at z=0.41. https://doi.org/10.1086/308517

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