Search for QSOs behind Abell Clusters using Burrell Schmidt BVRI CCD Photometry

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Session 19 -- Multiwavelength AGN Studies
Display presentation, Monday, 9, 1995, 9:20am - 6:30pm

[19.02] Search for QSOs behind Abell Clusters using Burrell Schmidt BVRI CCD Photometry

I.K.Horowitz (Idaho State University), J.W.Moody, E.Hintz (BYU)

Utilizing BVRI CCD photometry of two Abell clusters (Abell 2029 and Abell 2255) taken with the CWRU Burrell Schmidt 0.6/0.9m telescope at KPNO, a search has been undertaken for both lensed and high-z QSOs on the basis of point sources with unusual colors. The photometry is performed using the DoPHOT reduction package (Schecter, Mateo and Saha, 1993, PASP , 105 , 1353) to locate all point sources in a given image and provide an instrumental magnitude for each of them. From the measured (B-V), (V-R) and (R-I) colors, candidate objects which do not fall on the stellar locus are identified for followup spectroscopy.

Since these fields contain rich clusters of galaxies, it is probable that some of the successful QSO candidates may be lensed by the foreground cluster. Further reductions of an existing data set including 12 additional Abell cluster fields should provide a sizable sample of high-z QSOs with better than even odds of at least one of them being lensed.

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