\begin{table}%t2 
\caption{NGC~5218: observational results.}\label{results}
\small%\centerline
{
\begin{tabular}{lr} 
\hline \hline
Parameter & Value\\ 
\hline  
OVRO low resolution map &  \\
Integrated intensity, low resolution map &  93 Jy  \kms  \\
Maximum in one beam ($4\farcs38\times4\farcs08$) & 86 Jy \kms  \\
Molecular mass, low resolution map  & $1.3 \times 10^9~M_{\odot} $ \\
Maximum projected gas surface density  & 2600 $M_{\odot}$ \pcsquare \\
  & \\
OVRO high resolution map &  \\
Integrated intensity, high resolution map &  51 Jy  \kms  \\
Maximum in one beam ($1\farcs79\times1\farcs38$) & 34 Jy \kms  \\
Molecular mass, high resolution map  & $7 \times 10^8~M_{\odot} $ \\
Maximum projected gas surface density  & 10~000~$M_{\odot}$ \pcsquare  \\
  & \\
Radio continuum (robustly weighted) &  \\
Flux density detected with MERLIN   &  13.7 mJy \\
Maximum in one beam  ($0\farcs17\times0\farcs16$)  &  1.2 mJy \\
  & \\
Radio continuum (700 k$\lambda$ uv-tapered) &  \\
Flux density detected with MERLIN   &  26 mJy \\
Flux density detected with VLA$^{a}$  &  26.2 \& 27.2 mJy \\
& \\
OSO 20 m CO 1--0 results$^{b}$ &  \\
Integrated intensity, center position &  9.5 K~\kms \\
Integrated intensity, 30$''$ east &  6.5 K~\kms \\
Integrated intensity, 30$''$ west &  6.7 K~\kms \\
Integrated intensity, 30$''$ north &  No detection$^{c}$ \\
Integrated intensity, 30$''$ south & 2.5 K~\kms  \\
Integrated intensity, 45$''$ east &  1.0 K~\kms \\
Integrated intensity, 45$''$ west &  No detection$^{c}$ \\
& \\
OSO 20 m HCN and HCO$^+$ results$^{b}$ &  \\
Integrated intensity,  HCN &  0.45 K~\kms \\
Integrated intensity, HCO$^+$& 0.35 K~\kms \\
\hline 
\end{tabular}} 
\medskip
$^a$ Condon et~al. (\cite{Cond90}), in 15$''$ and 5$''$ beams respectively.
$^b$ In units of $T_{\rm A}^*$.
$^c$ At an rms noise level of 6 mK, at a resolution of 30 \kms.
\end{table}