GEMINI/GMOS SPECTROSCOPY OF 26 STRONG-LENSING-SELECTED GALAXY CLUSTER CORES
- Department of Astronomy and Astrophysics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
- Max-Planck-Institut fuer Astronomie Koenigstuhl 17, D-69117, Heidelberg (Germany)
- Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
- Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, N-0315 Oslo (Norway)
- Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitako, Tokyo 181-8588 (Japan)
We present results from a spectroscopic program targeting 26 strong-lensing cluster cores that were visually identified in the Sloan Digital Sky Survey (SDSS) and the Second Red-Sequence Cluster Survey (RCS-2). The 26 galaxy cluster lenses span a redshift range of 0.2 < z < 0.65, and our spectroscopy reveals 69 unique background sources with redshifts as high as z = 5.200. We also identify redshifts for 262 cluster member galaxies and measure the velocity dispersions and dynamical masses for 18 clusters where we have redshifts for N {>=} 10 cluster member galaxies. We account for the expected biases in dynamical masses of strong-lensing-selected clusters as predicted by results from numerical simulations and discuss possible sources of bias in our observations. The median dynamical mass of the 18 clusters with N {>=} 10 spectroscopic cluster members is M {sub Vir} = 7.84 x 10{sup 14} M {sub sun} h {sup -1} {sub 0.7}, which is somewhat higher than predictions for strong-lensing-selected clusters in simulations. The disagreement is not significant considering the large uncertainty in our dynamical data, systematic uncertainties in the velocity dispersion calibration, and limitations of the theoretical modeling. Nevertheless our study represents an important first step toward characterizing large samples of clusters that are identified in a systematic way as systems exhibiting dramatic strong-lensing features.
- OSTI ID:
- 21557061
- Journal Information:
- Astrophysical Journal, Supplement Series, Vol. 193, Issue 1; Other Information: DOI: 10.1088/0067-0049/193/1/8; ISSN 0067-0049
- Country of Publication:
- United States
- Language:
- English
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