\begin{table}%t1
%\centering
\par
\caption{Overview over the major heating and cooling processes in PDR physics.}\label{heatcool}
\begin{tabular}{ll}
\hline\hline
{Heating}&Cooling\\
\hline
photoelectric heating (dust \& PAH) & [CII] 158~$\mu$m\\
collisional de-excitation of vib. excited H$_2$&[OI] 63, 145~$\mu$m\\
H$_2$ dissociation& [CI] 370, 610~$\mu$m\\
H$_2$ formation& [SiII] 35~$\mu$m\\
CR ionization  & CO, H$_2$O, OH, H$_2$\\
gas-grain collisions&Ly $\alpha$, [OI], [FeII]\\
dissipation of turbulence& gas-grain collisions \\ \hline
\end{tabular}
\end{table}