An IR-selected galaxy cluster at z=1.27
- Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
- Department of Astronomy, University of Florida, Gainesville, Florida 32611 (United States)
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)
- Department of Astronomy, University of California, Berkeley, California 94720 (United States)
- National Optical Astronomy Observatories, Tucson, Arizona 85726 (United States)
We report the discovery of a galaxy cluster at z=1.27. ClG J0848+4453 was found in a near{endash}IR field survey as a high density region of objects with very red J{minus}K colors. Optical spectroscopy of a limited number of 24{approx_lt}R{approx_lt}25 objects in the area shows that 6 galaxies within a 90 arcsec (0.49h{sub 100}{sup {minus}1} Mpc, q{sub 0}=0.1) diameter region lie at z=1.273{plus_minus}0.002. Most of these 6 member galaxies have broad-band colors consistent with the expected spectral energy distribution of a passively-evolving elliptical galaxy formed at high redshift. An additional 2 galaxies located {approximately}2 arcmin from the cluster center are also at z=1.27. Using all 8 of these spectroscopic members, we estimate the velocity dispersion {sigma}=700{plus_minus}180 km s{sup {minus}1}, which is similar to that of Abell richness class R=1 clusters in the present epoch. A deep {ital ROSAT}/PSPC observation detects X-ray emission at the 4.5{sigma} level coincident with the nominal cluster center. Assuming that the X-ray flux is emitted by hot gas trapped in the potential well of a collapsed system (no AGN are known to exist in the area), the resulting X-ray luminosity in the rest frame 0.1{endash}2.4 keV band of L{sub x}=1.5{times}10{sup 44} ergs s{sup {minus}1} suggests the presence of a moderately massive system. ClG J0848+4453 is the highest redshift cluster found in a field survey. {copyright} {ital 1997 American Astronomical Society.}
- Research Organization:
- Lawrence Livermore National Laboratory
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 552814
- Journal Information:
- Astronomical Journal, Journal Name: Astronomical Journal Journal Issue: 6 Vol. 114; ISSN ANJOAA; ISSN 0004-6256
- Country of Publication:
- United States
- Language:
- English
Similar Records
An X-Ray[endash]Selected Galaxy Cluster at [bold [ital z]] = 1. 26
RX J0848.6+4453: The evolution of galaxy sizes and stellar populations in A z = 1.27 cluster