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Near Infrared Imaging of the Proposed z=2 Cluster Behind CL 0939+4713 (Abell 851)

J. B. Hutchings·T. J. Davidge
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Abstract

We have obtained deep J and K' images of a 90 arcsec square field containing the z=2.0 QSO that is viewed through the z=0.4 rich cluster A851. Brightnesses of individual galaxies are measured from these data, and archival F702W WFPC2 images from HST. The results are used to construct 2-colour diagrams, colour-magnitude diagrams, and luminosity functions of galaxies in A851 and the faint objects discovered by Dressler et al (1993) near the QSO. The QSO faint companions appear to form a separate population from other faint galaxies in the field. Comparisons with the GISSEL models covering redshifts from 0 to 3 indicate that (1) the A851 galaxies have ages between 3 and 10 Gyr, and (2) if they are at the QSO redshift, the QSO companion galaxies are within 1Gyr of cessation of star-formation.

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J. B. Hutchings, T. J. Davidge. 1997-03-06. Near Infrared Imaging of the Proposed z=2 Cluster Behind CL 0939+4713 (Abell 851). https://doi.org/10.1086/133929

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