Astronomy & Astrophysics

Free access article

A&A 394, 395-403 (2002)
DOI: 10.1051/0004-6361:20021195

Spectroscopy of the neighboring massive clusters Abell 222 and Abell 223

J. P. Dietrich¹, D. I. Clowe¹ and G. Soucail²

¹ Institut für Astrophysik und Extraterrestrische Forschung, Universität Bonn, Auf dem Hügel 71, 53121, Bonn, Germany
² Observatoire Midi-Pyrénées, UMR5572, 14 Av. Édouard Belin, 31400 Toulouse, France

(Received 29 May 2002 / Accepted 9 August 2002 )

Abstract
We present a spectroscopic catalog of the neighboring massive clusters Abell 222 and Abell 223 . The catalog contains the positions, redshifts, R magnitudes, V-R color, as well as the equivalent widths for a number of lines for 183 galaxies, 153 of them belonging to the A 222 and A 223 system. We determine the heliocentric redshifts to be $z=0.2126\pm0.0008$ for A 222 and $z=0.2079\pm0.0008$ for A 223. The velocity dispersions of both clusters in the cluster restframe are about the same: $\sigma = ^_$ km s ^-1 and $\sigma = ^_$ km s ^-1 for A 222 and A 223, respectively. While we find evidence for substructure in the spatial distribution of A 223, no kinematic substructure can be detected. From the red cluster sequence identified in a color-magnitude-diagram we determine the luminosity of both clusters and derive mass-to-light ratios in the R-band of $(M/L)_{{\rm A222}} = (202 \pm 43)~h_~M_{\odot}/L_{\odot}$ and $(M/L)_{{\rm A223}} = (149 \pm 33)~h_~M_{\odot}/L_{\odot}$ . Additionally we identify a group of background galaxies at $z \sim 0.242$ .

Key words: galaxies: clusters: general -- galaxies: clusters: individual: A 222 -- galaxies: clusters: individual: A 223 -- galaxies: distances and redshifts -- galaxies: luminosity function, mass function

Offprint request: J. P. Dietrich, dietrich@astro.uni-bonn.de

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