\begin{table}%t1
\caption{\label{t:abs}Abundances and column densities of \thco\ and \hho.}
%\centering
\par
\begin{tabular}{ccccc}
\hline \hline
\noalign{\smallskip}
Component & $N$(\thco)\tablefootmark{a}  & $N$(p-\hho)     & $N$(\hh) & $x$(p-\hho)\\
          & 10$^{16}$~\scm & 10$^{12}$~\scm & 10$^{21}$~\scm & \\ 
\hline\\[-3.2mm]
Dense core & \pow{7.8}{-7} & ...              & ... & \pow{1.6}{-10} \\
Outflow    & 5             & 10~000           & 15  & \pow{7}{-7} \\
Foreground & 0.7           & 4                & 2.1 & \pow{4}{-9} \\
\hline
\end{tabular}
\tablefoot{\tablefoottext{a}{Abundance for the dense core.}}
\vspace{-6mm}\end{table}