\begin{table}%t2           
\caption{Main results from the observations.\label{tab2}}             
%\centerline
{\begin{tabular}{l c c c c c c c}     % 7 columns 
\hline\hline       
                      % To combine 4 columns into a single one 
  &  & \multicolumn{4}{c}{Emission lines} &      & \\ 
 \cline{3-6}
Source & $z$ &  Id. & $\lambda _{\rm obs}$ & Flux  & {\it EW} (rest)  & $N_{\rm H}$ & 
$L_{2-10~\rm keV}$\\
        &   &      &  ($\mu$m)        & 10$^{-16}$ erg cm$^{-2}$ s$^{-1}$ & \AA &
	(10$^{22}$~cm$^{-2}$)	& (10$^{44}$~erg s$^{-1}$) \\
\hline                    
Abell2690\#029 & 2.0875 & H$\alpha$(broad) & 2.0266 $\pm$ 0.0015 & 20 $\pm$ 4 & 260 $\pm$ 50 & 2.2$^{+2.7}_{-1.7}$ & 9.7 \\
               &        & [OIII]5007       & 1.5457 $\pm$ 0.0008 & 1.2 $\pm$ 0.2 & 37 $\pm$ 7 &     &       \\
               &        & H$\beta$(broad)  & --     & $<$1 & -- &  &        \\
BPM16274\#069  & 1.3553 & [OIII]5007       & $1.1790\pm0.0002$ & $4.6\pm0.5$$^a$& $43\pm5$ & 2.6$^{+1.5}_{-1.0}$ & 3.9 \\ 
               &        & [OIII]4960       & $1.1680\pm0.0005$ & $1.7\pm0.5$$^a$& $13\pm4$ &     &     \\ 
               &        & H$\beta$(narrow) & $1.1446\pm0.0005$ & $2.1\pm0.6$$^a$& $21\pm6$     &	 \\ 
               &        & H$\alpha$(narrow)& $1.5463\pm0.0005$ & $2.3\pm0.7$$^a$& $10\pm3$    &	\\ 
               &        & [NII]6583        & $1.5502\pm0.0005$ & $2.8\pm0.7$$^a$& $12\pm3$     &	 \\ 
Abell2690\#075 & 2.13$^b$ & H$\alpha$(?)$^b$& $2.0574\pm0.0020$$^b$ & $0.81\pm0.15$$^b$ & $30\pm6$ & 36$^{+47}_{-22}$$^b$ & 15.0$^b$\\ 
\hline                  
\end{tabular}}
\par
\smallskip
$^a$  Highly uncertain flux calibration.
$^b$  Redshift and other derived quantities
 based on the tentative identification of the feature at 2.0574~$\mu$m with~H$\alpha$.
\end{table}