We present a dynamical analysis of the galaxy cluster AC114 based on a catalogue of 524 velocities. Of these, 169 (32%) are newly obtained at ESO (Chile) with the VLT and the VIMOS spectrograph. Data on individual galaxies are presented and the accur
acy of the measured velocities is discussed. Dynamical properties of the cluster are derived. We obtain an improved mean redshift value z= 0.31665 +/- 0.0008 and velocity dispersion sigma= 1893+73-82 kms. A large velocity dispersion within the core radius and the shape of the infall pattern suggests that this part of the cluster is in a radial phase of relaxation with a very elongated radial filament spanning 12000 kms. A radial foreground structure is detected within the central 0.5/h Mpc radius, recognizable as a redshift group at the same central redshift value. We analyze the color distribution for this archetype Butcher-Oemler galaxy cluster and identify the separate red and blue galaxy sequences. The latter subset contains 44% of confirmed members of the cluster, reaching magnitudes as faint as R_{f}= 21.1 (1.0 magnitude fainter than previous studies). We derive a mass M_{200}= (4.3 pm 0.7) x 10^15 Msun/h. In a subsequent paper we will utilize the spectral data presented here to explore the mass-metallicity relation for this intermediate redshift cluster.
Our research on the age-metallicity and mass-metallicity relations of galaxies is presented and compared to the most recent investigations in the field. We have been able to measure oxygen abundances using the direct method for objects spanning four
orders of magnitude in mass, and probing the last 4 Gyr of galaxy evolution. We have found preliminary evidence that the metallicity evolution is consistent with expectations based on age-metallicity relations obtained with low resolution stellar spectra of resolved Local Group galaxies.
As a part of our galaxy-cluster redshift survey, we present a set of 80 new velocities in the 4 clusters Abell 376, Abell 970, Abell 1356, and Abell 2244, obtained at Haute-Provence observatory. This set now completes our previous analysis, especiall
y for the first two clusters. Data on individual galaxies are presented, and we discuss some cluster properties. For A376, we obtained an improved mean redshift <z> = 0.047503$ with a velocity dispersion of sigma_V = 860 km/s. For A970, we have <z> = 0.058747 with sigma_V = 881 km/s. We show that the A1356 cluster is not a member of the Leo-Virgo supercluster at a mean redshift <z>= 0.112 and should be considered just as a foreground group of galaxies at <z> = 0.0689, as well as A1435 at <z> = 0.062. We obtain <z> = 0.099623 for A2244 with sigma_V = 965 km/s. The relative proximity of clusters A2244 and A2245 (<z> = 0.0873816, sigma_V = 992 km/s) suggests that these could be members of a supercluster that would include A2249; however, from X-ray data there is no indication of interaction between A2244 and A2245.
