\begin{table}%t3
%\centering
\par
\caption{Main  features in the optical spectra. 1. identification of the ULXs; 2. observed wavelength; 3. spectral line identification; 4. redshift.\label{tab3}}
\begin{tabular}{lcccc}
\hline\hline
\noalign{\smallskip}
 ID &  Spectral  (\AA) &  Identification  
&  Redshift  \\
  &  feature    &    
&     \\
\hline
IXO~29 \\
	 & 5154 & MgII($\lambda$2799 \AA)   & 0.8415 \\
	 & 6866 & OII($\lambda$3728 \AA)    & 0.8414 \\
	 & 7126 & NeIII($\lambda$3870 \AA)  & 0.8415 \\
	 & 8960?& H$\beta$		       & 0.8426 \\
	 & 9222 & OIII($\lambda$5007 \AA)   & 0.8413 \\	   
	\hline
IXO~43 \\
       & 4617 & OII ($\lambda$3728 \AA)   & 0.2384 \\
       & 6022  & H$\beta$		     & 0.2384 \\
       & 6141  & OIII($\lambda$4959 \AA)   & 0.2381 \\
       & 6203  & OIII($\lambda$5007 \AA)   & 0.2385 \\
       \hline
IXO~54 \\
       & 4646 &  MgII($\lambda$2799 \AA)  & 0.6601 \\ 
       & 6184  &  OII($\lambda$3728 \AA)   & 0.6586 \\
       & 6421 & NeIII($\lambda$3870 \AA)  & 0.6593 \\
       \hline
IXO~55 \\
	& 3380   & OIV($\lambda$1402 \AA)+SiIV($\lambda$1397 \AA) &   \\
	& 3735 & CIV ($\lambda$1549 \AA)	       & 1.4109  \\
	& 4603 & CIII ($\lambda$1909 \AA)	      & 1.4114 \\
	& 6758 & MgII ($\lambda$2799 \AA)	      & 1.4146 \\
      \hline
IXO~56 \\
	& 3529 & CIII($\lambda$1909 \AA) & 0.8491 \\
	& 4574 & OII($\lambda$2471 \AA)  & 0.8511 \\
	& 5178 & MgII ($\lambda$2799 \AA)& 0.8503 \\	   
	& 5901 & HeI($\lambda$3189 \AA)? & 0.8507 \\
	& 6890 & OII($\lambda$3728 \AA)  & 0.8463 \\
	& 7153 & NeIII($\lambda$3870 \AA)& 0.8468 \\	  
      \hline
IXO~57 \\
       & 5165  & MgII($\lambda$2799 \AA) & 0.8453 \\
       & 5914? & HeI($\lambda$3189 \AA)? & 0.8546 \\
       & 6910? & OII($\lambda$3728 \AA)  & 0.8538 \\
       & 7175  & NeIII($\lambda$3870 \AA)& 0.8540 \\
       \hline
IXO~70 \\
	& 3658  & CIV($\lambda$1549 \AA)   & 1.3628 \\
	& 3863  & HeII$\lambda$1640 \AA)   & 1.3548 \\
	& 4493  & CIII($\lambda$1909 \AA)  & 1.3535 \\
	& 6545? & MgII($\lambda$2799 \AA) & 1.3397 \\
	\hline
SW78 \\
	& 3358 &  CIV($\lambda$1549 \AA) & 1.1674 \\
	& 4153 & CIII($\lambda$1909 \AA) & 1.1760 \\
	& 6126 & MgII($\lambda$2799 \AA) & 1.1887 \\
	\hline	
\end{tabular}
\end{table}