\begin{table}%t6
\caption{\label{t:ColDens}Column densities from single peaked \HCOp\ profiles.}
%\centering
\small
\begin{tabular}{lr@{}c@{}lr@{}c@{}lcccc}
\hline\hline\noalign{\smallskip}
Source	     & \multicolumn{3}{c}{$T_{\rm A}^*$(\HCOp)} & \multicolumn{3}{c}{$\Delta v$} & $N_{J=3}$
             & $T_{\rm ex}^{(a)}$                    & $N$(\HCOp)  & $N$(H$_2$)$^{(b)}$ \\
	     & \multicolumn{3}{c}{K}              & \multicolumn{3}{c}{\km}       & cm$^{-2}$ 
             & K                                    &  cm$^{-2}$&	cm$^{-2}$\\
\hline\noalign{\smallskip}
G12.21-0.10  & 5.8 &$\;\pm\;$&.2 & 6.4&$\;\pm\;$&.3&\dex{(4.6\pm0.3)}{12} &  3.8 &\dex{9.9}{13}&\dex{4.9}{22} \\
G29.92-0.02  & 9.6 &     &.3 & 5.4&     &.2&\dex{(6.5\pm0.5)}{12} & 21.1 &\dex{3.1}{13}&\dex{1.5}{22} \\
G30.54+0.02  & 2.8 &     &.2 & 4.3&     &.3&\dex{(91.5\pm0.2)}{12}&  8.1 &\dex{1.9}{13}&\dex{9.7}{21} \\
G45.12+0.13  & 6.3 &     &.2 & 5.0&     &.2&\dex{(3.9\pm0.3)}{12} & 14.8 &\dex{2.2}{13}&\dex{1.1}{22} \\
G70.29+1.60* & 8.5 &     &.3 & 7.4&     &.2&\dex{(7.8\pm0.5)}{12} & 19.0 &\dex{3.8}{13}&\dex{1.9}{22} \\
G111.61+0.37 & 6.2 &     &.2 & 2.4&     &.3&\dex{(1.9\pm0.2)}{12} & 14.6 &\dex{1.1}{13}&\dex{5.4}{21} \\
\hline	      
\end{tabular}					
\tablefoot{\tablefoottext{a}{Assumed \Tex~$\geq$ $2.7 + 1.92~{T}_{\rm A}^*$;}
\tablefoottext{b}{assumed [H2]/[HCO+]~= $5$~$\times$ $10^8$. An~uncertainty of 50\% is adopted for $N$(\HCOp); see~text.}}
\end{table}