\begin{table}%t2
\caption{\label{fidpam}Parameters of the fiducial photoionization model.}       
%\centering
\par
\begin{tabular}{l l l}       
\hline\hline \noalign{\smallskip}               
Parameter & Value & Unit \\    
\hline                        
$T_{\rm bb}$ &100 & kK\\
$\log(U)$ &$-1$\\
$Z_{\rm neb}$ & $0.05~Z_{\odot}$\\
$Q$(H) & $3 \times 10^{55}$& s$^{-1}$\\
$n_{\rm H}$ & $10^{2.9}$ & cm$^{-3}$\\
$r_{\rm in}$ & $10^{21}$ & cm\\
\hline                              
\end{tabular}
\end{table}