A redshift survey of the strong-lensing cluster abell 383

Abstract

Abell 383 is a famous rich cluster (z = 0.1887) imaged extensively as a basis for intensive strong- and weak-lensing studies. Nonetheless, there are few spectroscopic observations. We enable dynamical analyses by measuring 2360 new redshifts for galaxies with r Petro ≤ 20.5 and within 50′ of the Brightest Cluster Galaxy (BCG; R.A.2000 = 42.°014125, decl.2000 = -03.°529228). We apply the caustic technique to identify 275 cluster members within 7 h -1 Mpc of the hierarchical cluster center. The BCG lies within -11 ± 110 km s-1 and 21 ± 56 h -1 kpc of the hierarchical cluster center; the velocity dispersion profile of the BCG appears to be an extension of the velocity dispersion profile based on cluster members. The distribution of cluster members on the sky corresponds impressively with the weak-lensing contours of Okabe et al. especially when the impact of foreground and background structure is included. The values of R 200 = 1.22 ± 0.01 h -1 Mpc and M200 = (5.07 ± 0.09) × 1014 h -1 M⊙ obtained by application of the caustic technique agree well with recent completely independent lensing measures. The caustic estimate extends direct measurement of the cluster mass profile to a radius of ∼5 h -1 Mpc. © 2014. The American Astronomical Society. All rights reserved.