\begin{table}%t3
%\centering
\par
\caption{\label{taberr}``Extraction and fit'' errors (in km~s$^{-1}$) for each field and different $S/N$ range.}
\small \begin{tabular}{cccc}
\hline \hline
$S/N$  &  \multicolumn{3}{c}{Field} \\
  &  NGC~5986  &  M~80a  &  M~80b \\
\hline
$\geq$80  &  1.2  &  1.2  &  1.0 \\
40--80  &  2.1  &  3.0  &  3.0 \\
$\leq$40  &  6.3  &  5.0  &  5.4 \\
\hline
\end{tabular}
\end{table}