\begin{table}%t2
%\centering
\par
\caption{\label{Tab_2}Summary of observations and data reduction.}
\small \begin{tabular}{l r r r}
\hline \hline
Name of telescope  &  & \multicolumn{2}{c}{WSRT} \\
Total on-source integration time ($\rm h$)  & $t_{\rm obs}$       & \multicolumn{2}{c}{$4\times 12$}    \\
Observation dates   & \multicolumn{3}{c}{19--20/12/02, 21-22/12/02, 7--8/01/03, 8--9/01/03}     \\
\hline                                                                     Resolution of data cube  &     & High            & Low                 \\
\hline                                                                     
Weighting scheme  & & Uniform         & Robust 0.4          \\
Pixel size ($~\arcsec$) & d$x$   & $ 4 $  & $ 7     $           \\
Channel width (${\rm km}~{{\rm s}^{-1}}$) & d$v$  & $ 2.06$ & $ 4.12$ \\
Velocity resolution (${\rm km}~{{\rm s}^{-1}}$) & ${\it FWHM}_{\rm V}$    & $4.12$ & $8.24$ \\
Half-power-beam-width along the beam major axis ($~\arcsec$)              & ${\it HPBW}_{\rm maj}$   & $ 13.7  $       & $ 28.4  $           \\
Half-power-beam-width along the beam minor axis ($~\arcsec$) & ${  HPBW}_{\rm min}$  & $ 12.0  $       & $ 25.6  $           \\
Beam position angle ($~\deg$) & ${\rm PA}_{\rm beam}$   & $ -0.6  $       & $ 10.6$ \\
rms noise (${\rm mJy}/{\rm beam}$) in the data cubes & $\sigma_{\rm rms}$   & $ 0.42$& $0.24$ \\
rms noise per velocity resolution element ($10^{19}~{\rm atoms}~{\rm cm}^{-2}$) & $\sigma_{\rm rms}^{N}$  & $ 1.16  $ & $ 0.30  $           \\
\hline                               
Name of telescope/instrument                                                                      &                                             & \multicolumn{2}{c}{INT WFC}         \\
Total on-source integration time ($\rm s$)                                                        & $t_{\rm obs}$                               & \multicolumn{2}{c}{13~350} \\
Observing dates  & & \multicolumn{2}{c}{26/02-04/03/04}  \\
rms noise in the optical image (${\rm mag}~{\rm arcsec}^{-2}$)             & $\sigma_{{\rm i}^\prime} $   & \multicolumn{2}{c}{$ 25.8 $}        \\
rms noise in the optical image, $5~\sigma_{\rm rms}$-level for a $2\arcsec$ aperture ($\rm mag$) & $\sigma_{{\rm i}^\prime,2^{\prime\prime}} $ & \multicolumn{2}{c}{$ 21.3 $} \\
\hline
\end{tabular}
\end{table}