\begin{table}%t8 %\centering \par \caption{\label{param-13co63TOTspec}Summary of the parameters of the total integrated $^{13}$CO(1--0) emission of the GMC surrounding~G19.61--0.23 and of a typical cloud in Henize~2--10, from SMA observations.} \smallskip \begin{tabular}{c c c c c} \hline\hline \noalign{\smallskip} $FWHM$ & $M_{\rm VIR}$ & $M_{\rm LTE}$ & $\Sigma_{\rm VIR}$ & $\Sigma_{\rm LTE}$ \\ (km~s$^{-1}$) & ($\times$$10^5~M_{\odot}$) & ($\times$$10^5~M_{\odot}$) & (g/cm$^{2}$) & (g/cm$^{2}$) \\ (1)&(2)&(3)&(4)&(5)\\ \hline \multicolumn{5}{c}{{G19.61--0.23}} \\ 8 & 5 & 4 & 0.02 & 0.02 \\ \hline \multicolumn{5}{c}{{Henize~2--10}} \\ 20 & 39 & 30 & 0.13 & 0.10 \\ \hline \end{tabular} \tablefoot{Column~(1): $FWHM$ line-width of the emission; Col.(2): virial mass; Col.~(3): LTE mass, assuming $T_{\rm ex} = 20$~K; Col.~(4): surface density from the virial mass; Col.~(5): surface density from the LTE mass.} \end{table}