Tunable-Filter Imaging of Quasar Fields at z ~ 1. I. A Cluster around MRC B0450−221

  title={Tunable-Filter Imaging of Quasar Fields at z ~ 1. I. A Cluster around MRC B0450−221},
  author={Joanne C. Baker and Richard W. Hunstead and Malcolm N. Bremer and Joss Bland-Hawthorn and Ramana Athreya and Jordi McGregor Barr},
  journal={The Astronomical Journal},
Using a combination of multicolor broadband and narrowband imaging techniques and follow-up spectroscopy, we have detected an overdensity of galaxies in the —eld of quasar MRC B0450[221, whose properties are consistent with a cluster at the quasar redshift z \ 0.9. An excess of red galaxies (V [I [ 2.2, I[K@ ” 3.8) is evident within 1@ of the quasar, with the colors expected for galaxies at z \ 0.9 that have evolved passively for 3 Gyr or more. A number of line-emitting galaxies (nine… Expand
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