GALAXY CLUSTERS WITH QSOS AT REDSHIFT 1.1

We report imaging of z approximately 1.1 QSO fields with R, I, and 75 A narrow-band filters tuned to the redshift wavelength of [O II] 3727 angstrom. The data presently in hand cover four radio-quiet QSOs and one radio loud, as well as a radio galaxy and a radio QSO at z approximately 0.6, where the narrow-band filter isolates [O III] 5007 A. In this paper we give details on the radio-loud and one of the radio-quiet z approximately 1.1 QSOs. In both we find an excess of faint galaxies near the QSO, many of which are very blue. We also find that several of these have emission-line detections, suggesting they are at the same redshift as the QSO. We discuss the statistics of these objects and conclude that we are seeing clusters of compact galaxies at z=1.1, most of which are starbursting. Preliminary analyses of all our fields suggest that they also contain similar clusters.