\begin{table}%[ht]%t3 \par %\centering \par \caption{\label{col_data} Column densities of \coiso\ and \moloiso.} \par \begin{tabular}{cccccc} \hline \hline \noalign{\smallskip} $T_{\rm k}$ & $A_{3,2}/\gamma_{3,2}$ & $N$(\coiso) & $A_{21,01}/\gamma_{21,01}$ & $N$(\moloiso) & {\underline{$N$(\coiso)}} \\ (K) & (\cmthree) & (\cmtwo) & (\cmthree)\tablefootmark{a} & (\cmtwo)\tablefootmark{b} & $N$(\moloiso) \\ \noalign{\smallskip} \hline \noalign{\smallskip} 300 & $3.4 \times 10^{4}$ &$4.9 \times 10^{16}$ & $2.7 \times 10^{2}$ & $<$$5.6 \times 10^{15}$ & $>$$9$ \\ 100 & $4.0 \times 10^{4}$ &$2.0 \times 10^{16}$ & $4.7 \times 10^{2}$ & $<$$2.0 \times 10^{15}$ & $>$$10$ \\ \phantom{1}40 & $1.7 \times 10^{5}$ &$1.2 \times 10^{16}$ & $7.4 \times 10^{2}$ & $<$$9.5 \times 10^{14}$ & $>$$14$ \\ \phantom{1}20 & $1.7 \times 10^{5}$ &$1.4 \times 10^{16}$ & $1.0 \times 10^{3}$ & $<$$6.3 \times 10^{14}$ & $>$$22$ \\ \phantom{1}10 & $1.7 \times 10^{5}$ &$3.2 \times 10^{16}$ & $1.5 \times 10^{3}$ & $<$$5.5 \times 10^{14}$ & $>$$59$ \\ % \noalign{\smallskip} \hline \end{tabular} \tablefoot{ \tablefoottext{a}{Collision rate coefficient $\gamma(T) = 4.9 \times 10^{-11}~~(T/300~{\rm K})^{0.5}~{\rm cm^3~s^{-1}}$.} \\ \tablefoottext{b}{Limits on $N$(\moloiso) are $1 \sigma$; $f_{\rm b} = 1.0$ and \tadv~$< 3.3$~mK \kms.}} \end{table}