\begin{table}%t1
\caption{\label{table_model}Model $L_{\rm X}/L_{\rm UV}$ ratios.}        
%\centering
\par
\small \begin{tabular}{l c c}        
\hline\hline                 
         Case       & Class S &  Class~Q \\    
\hline
         A & 0.40 $\dot{M}_{0}/M_{8}$  & 0.01 $\dot{M}_{1}/M_{9}$ \\         
         B & 0.17 & --\\                     
\hline                               
\end{tabular}
\end{table}