\begin{table}%t1
\par
        \caption {Main parameters for the cluster sample. The cluster denominations  come from \citet[][VMF]{vik98}  
and \citet[][XDCS]{gilbank04}.  Coordinates are  given with respect   to the X-ray centroid.  X-ray fluxes are taken from
 \citet{mullis03}.  \Rv\ is the virial radius and~$\sigma$ the velocity dispersion.  $N$ is the number of  members
 identified  in each cluster.\label{T:maindata}}
	%\centerline
 { \begin{tabular}{l l l l l l l l l l l}
 \hline\hline 
	   Field  & Cluster & Alternative name & RA & Dec & $z$  & $f_{\rm X}$ &  $L_{\rm X,bol}$  & $\sigma$ & \Rv & $N$\\
	              &       &          &               &       &   &  [10$^{-14}$~erg/s cm$^2$] & [10$^{43}$~erg/s] & [km~s$^{-1}$] & [Mpc]  &  \\
	   \hline
R220 & \object{VMF194}  &   \object{RX~J1729.0+7440} & 17:29:02 & 74:40:46  & 0.210 & 17.3 & 5.01 & 282~$\pm$~52  & 0.742 & 8  \\
	  & \object{XDCS220} & \object{cmJ172333+744410}$^1$ & 17:23:33 & 74:44:10 & 0.261 & 0.3 & 0.14 & 621~$\pm$~271$^2$  & 1.535 & 15 \\
R265  & \object{VMF131}  &  \object{RX~ J1309.9+3222} & 13:09:56 & 32:22:31 & 0.294 & 9.0  & 6.03 & 476~$\pm$~110 & 1.132 & 29 \\
	   & \object{VMF132}  &  \object{RX~ J1313.2+3229} & 13:11:13 & 32:28:58 & 0.247 & 46.7 & 24.5 & 774~$\pm$~150 & 1.945 & 18\\
R285  & \object{VMF73}   &  \object{RX~ J0943.5+1640} & 09:43:32 & 16:40:02   & 0.254 & 23.1 & 12.3 & 661~$\pm$~65  & 1.647 & 44 \\
	   & \object{VMF74}   &   \object{RX~ J0943.7+1644} & 09:43:45 & 16:44:20  & 0.180 & 21.2 & 4.79 & 481~$\pm$~79  & 1.313 & 34 \\
	   \hline\\
	 \end{tabular}}
\smallskip
$^1$ \citet{gilbank04}\\
$^2$ This  value is likely overestimated, since the cluster does not seem to be in dynamical equilibrium, see text for details	 
   \end{table}