\begin{table}%T4
\par
%\centering
\par
\caption{Parameters used for a three Gaussian component description of the JCMT
beam.}
\label{tab:gaussian components}
  \begin{tabular}{cccc}
    \hline
    \hline
    \multicolumn{2}{c}{850 $\mu$m} &\multicolumn{2}{c}{450 $\mu$m} \\
    %\cmidrule(r){1-2}\cmidrule(l){3-4}
    \multicolumn{1}{c}{Relative} &\multicolumn{1}{c}{{\it FWHM}} &\multicolumn{1}{c}{Relative} &\multicolumn{1}{c}{{\it FWHM}} \\
    \multicolumn{1}{c}{Amplitude} &\multicolumn{1}{c}{($''$)} &\multicolumn{1}{c}{Amplitude} &\multicolumn{1}{c}{($''$)} \\
    \hline
    0.93 &14.4 &0.81 &8.0  \\
    0.05 &44.3 &0.17 &24.7 \\
    0.02 &62.9 &0.02 &71.3 \\
    \hline
  \end{tabular}
\end{table}