Extremely Red Objects in the Field of QSO 1213-0017: A Galaxy Concentration at z=1.31


Abstract in English

We have discovered an excess of extremely red objects (EROs) surrounding the z=2.69 quasar QSO 1213-0017 (UM 485). Optical/IR colors for these galaxies are consistent with z=1-2 ellipticals, and there are at least 5 galaxies with spectroscopic redshifts at <z>=1.31. Keck optical spectra for 3 of the red galaxies show rest-frame UV breaks resembling local elliptical galaxies. Our initial results suggest a coherent structure in redshift, possibly arising from a massive galaxy cluster.

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