THE ASTRONOMICAL JOURNAL
AUGUST 1995
VOLUME 110, NUMBER 2, PAGE 463
THE SHAPLEY SUPERCLUSTER. I. SPECTROSCOPIC OBSERVATIONS
IN THE CENTRAL REGION
H. QUINTANA AND A. RAMIREZ
Grupo de Astrofisica, P. Universidad Catolica de Chile, Santiago,
Chile
Electronic mail: hquintan@astro.puc.cl
JORGE MELNICK
European Southern Observatory, La Silla, Chile
Electronic mail: jmelnick@eso.org
SOMAK RAYCHAUDHURY
Harvard-Smithsonian Center for Astrophysics, Cambridge,
Massachusetts
ERIC SLEZAK
Observatoire de la Cote d'Azur, BP 229, F06304, Nice Cedex 4, France
Electronic mail: slezak@rameau.obs-nice.fr
ABSTRACT
We present a new analysis of the kinematics of the Shapley
supercluster
based on radial velocities for 1087 galaxies in the clusters A3558
(Shapley 8), A3528 (Klemola 21), A3532 (Klemola 22), A3530, A3556 (SC
1321-314), A3559 (CE 1327-292), A3560, A3562, SC 1329-314 and in the
intercluster region of the core of the supercluster, of which 367 are
new measurements. We also present accurate positions from APM and
MAMA
scans of the ESO/SERC Southern Sky Survey photographic plates. We
obtain new velocity dispersions and estimate the masses of the member
clusters, evaluating dynamical models of the supercluster. The
supercluster is found to be significantly flattened. We find that
for
Omega_0=0.3, H_0=75 km/s/Mpc, the gravitational pull of the
supercluster may account for up to 25% of the peculiar velocity of
the
Local Group required to explain the dipole anisotropy of the Cosmic
Microwave Background radiation, in which case the mass of the
supercluster would be dominated by intercluster dark matter. This
fractional contribution would be considerably higher for combinations
of significantly lower values of Omega_0 and higher values of H_0.