\begin{table}%t5
\caption{\label{tau:tab}Lengths and dynamical age of the flows.}
%\centering
\small
\begin{tabular}{cccc}
\hline \hline
 Knot   & Possible &  Length &  $\tau_{\rm dyn}$  \\
  ID	& exciting source   &   (pc)  &	 (10$^3$ yrs) \\
\hline
HH~52~A   &  IRAS~12416-7703      & 3.9  & 39  \\
HH~54~C   &  IRAS~12416-7703      & 4.2  & 63         \\
HH~54~G   &  IRAS~12416-7703      & 4.2  & 41    \\
HH~54~A   &  IRAS~12416-7703      & 4.2  & 63    \\
HH~53~A-C &  Source~2           & 0.1--0.2 & 0.3--0.8   \\
HH~54~Y   &  IRAS~12500-7658      & 2.1  &  18  \\
HH~54~K-E &  IRAS~12500-7658      & 2.2  &  43  \\
\hline
\end{tabular}
\end{table}