\begin{table}%t1
%\centering
\par
\caption{ \label{para}Input parameters for the three PWNe.}
\begin{tabular}{lcccc}
\hline \hline\\[-3mm]
{Parameter} & {G0.9+0.1} & {MSH 15-52} & {G338.3-0.0 (case 1)} & {G338.3-0.0 (case 2)} \\
\hline
Distance (kpc)              & 8.5             & 5.2         &  10.0   & 10.0    \\
$T_{\rm age}$ (yr)          & 1900            & 1900        &  4500   & 8200    \\
$\tau_{\rm sd}$ (yr)        & 500             & 500         &   500   & 500     \\
$M_{\rm ej}$ ($M_{\odot}$)  & 8.0             & 8.0         &   8.0   &  8.0    \\
$E_{\rm sn}$ ($10^{51}$erg) & 1.0             & 3.0         &   0.5   & 0.8     \\
$n_{\rm ism}$ (cm$^{-3}$)   & 0.01            & 0.01        &   0.1   & 1.0     \\
$\dot{E_0}$ ($10^{39}$ erg s$^{-1}$)  & 2.0   &  1.5        &   10    & 0.5     \\
$n$                         & 3.0             & 2.84         &   3.0  & 3.0     \\
$\eta_{\rm B}$ ($10^{-3}$)  & 1.0             &  20.0        &   1.0  & 0.3     \\
$\alpha$                    & 2.5             &  2.4        &  2.5    & 2.5     \\
$E_{\rm max}$ (TeV)         & 900             &  1000       &  500    & 500     \\
$E_{\rm b}$  ($10^5$~MeV)    & 0.2             &  0.9        &  0.8    & 0.8     \\
\hline
\end{tabular}
\end{table}