Weak‐Lensing Discovery and Tomography of a Cluster at z = 0.68
We report the weak-lensing discovery, spectroscopic confirmation, and weak-lensing tomography of a massive cluster of galaxies at z = 0.68, demonstrating that shear selection of clusters works at redshifts high enough to be cosmologically interesting. The mass estimate from weak lensing, 11.1 ± 2.8 × 10^(14) (r/Mpc) M☉ within projected radius r, agrees with that derived from the spectroscopy (σ_v= 980 km s^(-1)) and with the position of an arc that is likely to be a strongly lensed background galaxy. The redshift estimate from weak-lensing tomography is consistent with the spectroscopy, demonstrating the feasibility of baryon-unbiased mass surveys. This tomographic technique will be able to roughly identify the redshifts of any dark clusters that may appear in shear-selected samples up to z ~ 1.
Additional Information© 2003 The American Astronomical Society. Received 2002 October 3; accepted 2003 July 10. We thank NOAO for supporting survey programs and the 2dFGRS project for making data publicly available. Observations were obtained at Cerro Tololo Inter-American Observatory (CTIO) and the W. M. Keck Observatory. CTIO is a division of National Optical Astronomy Observatory (NOAO), which is operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. The W. M. Keck Observatory is operated jointly by the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. This work also made use of IRAF and of the NASA/IPAC Extragalactic Database.
Published - Wittman_2003_ApJ_597_218.pdf
Accepted Version - 0210120.pdf