\begin{table}%t4
\caption{Recombination time-scale for atomic states at~$T_{\rm e}=10~000$~K for electron densities~$n_{\rm e}$ of~100 and~$200$~e$^-$~cm$^{-3}$. An increase of the electron density to
$n_{\rm e}=300$~e$^-$~cm$^{-3}$ only lowers the upper limits. The terms~"r'' and~"d'' refer to the radiative and dielectronic components in the total recombination coefficient~"t''.} \label{recombitab}
%\centering
\par
\begin{tabular}{lrr}
\hline \hline
State & $\tau_r(n_{\rm e}=100)~[{\rm yr}]$ & $\tau_r(n_{\rm e}=200)~[{\rm yr}]$\\
\hline 
H$^0$ &   760~~~    & 380~~~\\
He$^0$ & 1500~~~ & 750~~~\\
He$^+$  & 206~~~ & 103~~~\\
O$^{2+}$(r)  & 31~~~ & 16~~~\\
O$^{2+}$(d)  & 28~~~ & 14~~~\\
O$^{2+}$(t)  & 19~~~ & 9~~~\\
O$^+$(r)  & 155~~~ & 78~~~\\
O$^+$(d)  & 190~~~ & 95~~~\\
O$^+$(t)  & 85~~~ & 43~~~\\
N$^+$(r)  & 139~~~ & 70~~~\\
N$^+$(d)  & 155~~~ & 78~~~\\
N$^+$(t)  & 73~~~ & 37~~~\\
\hline 
\end{tabular}
\end{table}