\begin{table}%t6
\caption{\label{galmodel}Radiative transfer model parameters.}
%\centerline
{
\small\begin{tabular}{lccccccccccccc}
\hline\hline
No. & \multicolumn{3}{c}{Component 1} & \multicolumn{3}{c}{Component 2} & Emiss.&\multicolumn{6}{c}{Model ratios}\\
     & Kin.       & Gas	& Gradient & Kin.   & Gas      & Gradient    & ratio &\multicolumn{3}{c}{$\co$} &\multicolumn{3}{c}{$\co/\treizeco$}\\
     & temp.      & dens.    &${N({\rm CO})\over {\rm d}V}$  & temp.  & dens.    & $\textstyle{N({\rm CO})\over {\rm d}V}$ & Comp. 1:2 &$\textstyle{(1-0)\over (2-1)}$&$\frac{(3-2)}{(2-1}$&$\textstyle{(4-3)\over (2-1)}$ & (1--0) & (2--1) & (3--2) \\
     & $T_{\rm k}$  & $n({\rm H_{2}}$) & 	  & $T_{\rm k}$ & $n({\rm H_{2}}$)    & 1:2 & \multicolumn{6}{c}{}\\
     & (K)     	    & ($\cc$)    & ($\textstyle{~{\rm cm^{-2}}\over \kms}$) & (K) 	& ($\cc$) &($\textstyle{~{\rm cm^{-2}}\over \kms}$) &\\
\hline
\multicolumn{14}{l}{NGC~278  }\\
 1 & 100 &  500 &  $10\times10^{17}$ &  30 &  10~000 & $0.3\times10^{17}$ & 3:17 &0.92&0.79&0.52& 8.0& 8.9&11.0\\
 2 & 150 &  100 &  $30\times10^{17}$ &  30 &  10~000 & $0.3\times10^{17}$ & 1:4  &0.94&0.80&0.53& 8.2& 9.2&11.5\\
\multicolumn{14}{l}{NGC~660  }\\
 3 & 150 &  500 & $0.6\times10^{17}$ &  20 & 100~000 & $0.3\times10^{17}$ &11:9  &1.17&0.75&0.49&15.8&11.8&12.9\\
 4 & 150 &  100 & $0.6\times10^{17}$ & 150 &   3000 & $1.0\times10^{17}$ & 4:1  &1.17&0.72&0.50&16.3&12.3&12.1\\
\multicolumn{14}{l}{NGC~3628 }\\
 5 & 150 & 1000 & $3.0\times10^{17}$ &  20 &  10~000 & $0.3\times10^{17}$ & 1:9  &1.10&0.74&0.43&12.8&12.2& 8.9\\
 6 &  20 &  100 & $1.0\times10^{17}$ &  30 &  10~000 & $0.6\times10^{17}$ &17:3  &1.32&0.63&0.47&12.4&12.3& 8.7\\
\multicolumn{14}{l}{NGC~4631 }\\
 7 & 150 & 1000 & $1.0\times10^{17}$ &  10 &    300 & 0.45$\times10^{17}$& 1:5  &1.52&0.65&0.42&13.5&10.5&13.2\\
\multicolumn{14}{l}{NGC~4666 }\\
 8 & 100 & 1000 & $1.0\times10^{17}$ &  10 &  10~000 & 0.6$\times10^{17}$ & 7:13 &1.32&0.70&0.37& 8.5& 6.7&11.7\\
\hline
\end{tabular}}
\end{table}