All Tables

Table 1: Imaging: summary of the observations.
Table 2: Properties of the cz distribution and significance levels of shape estimators for various subsamples of A3921. ${C}_{\rm BI}$ and ${S}_{\rm BI}$ are the mean velocity and the velocity dispersion of the different distributions (biweight estimators for location and scale, Beers et al. 1990).
Table 3: 1-D statistical tests performed in the ROSTAT package that exclude the hypothesis of a single Gaussian distribution for the different velocity datasets considered in the paper. In Cols. 1 and 2 we report the name and the value of the statistics, while Col. 3 indicates their significance levels.
Table 4: 3-D substructure indicators for the sample of 104 objects with quality flag = 1 in the velocity range 25 400 $\div$ 30 400 km s^-1.
Table 5: Columns 1 and 2: projected virial radii of A3921-A and A3921-B; Cols. 3 and 4: virial mass estimates for A3921-A and A3921-B; Col. 5: mass ratio. Masses are in $10^{14}~ {M}_{\odot}$ units and radiii in h^-1 Mpc units.
Table 6: Column 1: name of the scenario in the text - Col. 2: time since last interaction between the two clumps - Col. 3: angle between the plane of the sky and the line connecting the centres of the two clumps - Col. 4: relative velocity between the two clumps - Col. 5: spatial separation between the two systems - Col. 6: state of the systems for the possible solutions.
Table 7: Number of spectra in different magnitude sub-samples. Bright and faint galaxies correspond to objects with $M_{R_{\rm AB}}<-20$ and $M_{R_{\rm AB}}>-20$ respectively. Bright objects correspond to the same sampling in absolute magnitude as in the MORPHS spectroscopic catalogue (Dressler et al. 1999).
Table 8: Properties of the cz distribution for the different spectral types. ^* In the case of the two separate k+a and k+a? subsamples we use the classical variance estimator for velocity dispersion and not the biweight indicator, owing to the low number of objects (Beers et al. 1990).