We report radial velocities for 99 galaxies with projected positions within 30 \arcmin of the center of the cluster A3733 obtained with the MEFOS multifiber spectrograph at the 3.6-m ESO telescope .
These measurements are combined with 39 redshifts previously published by Stein ( 1996 ) to built a collection of 112 galaxy redshifts in the field of A3733 , which is used to examine the kinematics and structure of this cluster .
We assign cluster membership to 74 galaxies with heliocentric velocities in the interval 10 500 – 13 000 \mbox { km s } ^ { -1 } .
From this sample of cluster members , we infer a heliocentric systemic velocity for A3733 of 11 653 ^ { +74 } _ { -76 } \mbox { km s } ^ { -1 } , which implies a mean cosmological redshift of 0.0380 , and a velocity dispersion of 614 ^ { +42 } _ { -30 } \mbox { km s } ^ { -1 } .
The application of statistical substructure tests to a magnitude-limited subset of the latter sample reveals evidence of non-Gaussianity in the distribution of ordered velocities in the form of lighter tails and possible multimodality .
Spatial substructure tests do not find , however , any significant clumpiness in the plane of the sky , although the existence of subclustering along the line-of-sight can not be excluded .