\begin{table}%t4[ht]
\caption{$\tau_{912}$ obtained from the column densities listed in Table~\ref{tab2}
(with $f =0$) and in Table~\ref{tab3}.\label{tab4}}
%\centering
\par
\begin{tabular}{ccc}
\hline\hline  
Filament & Model A  & Model B \\
\hline
%    &                &             \\
FP1 &  2.6 $\pm$ 0.6 & 6.4 $\pm$ 1.5\\
\par
F2  &  3.5 $\pm$ 1.5 & 8.4  $\pm$ 3.7 \\
\par
F3  &   3. $\pm$ 1. &  7. $\pm$ 2.4 \\
\hline 
\end{tabular}%\vspace*{2mm}
\end{table}