\begin{table}%t2
\caption{\label{table2}Instrumental setup.}
%\centering
\par
\begin{tabular}{llll}
\hline \hline \noalign{\smallskip}
\multicolumn{1}{c}{Parameters} & \multicolumn{3}{c}{Values}\\
\hline
\hspace{-0.1cm}HCG observation: \\
Telescope & CFHT 3.6 m  & CFHT 3.6 m & ESO 3.6 m  \\
Equipment  &  MOS/FP &  MOS/FP  & CIGALE  \\
Date   & 1996 Aug.  & 2000 Mar. &  2000 Sep.  \\
\hspace{-0.1cm}Calibration: \\
Neon light   & $\lambda$ 6598.95 \AA  & $\lambda$ 6598.95 \AA & $\lambda$ 6598.95 \AA   \\
Interferometer order at H$\alpha$  & 1162  & 1162 & 793 \\
Free spectral range at H$\alpha$ (km s$^{-1}$) & 265  & 258 &  378 \\
\hspace{-0.1cm}Sampling: \\
Number of scanning steps   & 24  & 28 & 32 \\
Sampling steps \AA (km s$^{-1}$) & 0.24 (11.0)  & 0.21 (9.2) & 0.26 (11.8) \\
\hspace{-0.1cm}Detector:
    &  CCD & CCD &  IPCS \\
\hline
\end{tabular}
\vspace*{2.1mm}
\end{table}