\begin{table}%t2
     \caption{Best fit parameters for the nonthermal
                component (\sbs).}
        \label{tab:parameter}%\centering
\small
\begin{tabular}{@{}cccc@{}}\hline\hline
Model & $l_{\rm nt}\tau_{\rm nt}(5~{\rm~GHz})$ & $\chi^2$
& $\chi_\nu^2$ \\
& (W Hz$^{-1}$ yr) & & \\
\hline
E & $7.6\times 10^{22}$ & 6.8 & 1.4 \\
F & $22\times 10^{22}$ & 34 & 6.8 \\
G & $5.8\times 10^{22}$ & 11 & 2.2 \\
H & $19\times 10^{22}$ & 4.0 & 0.8 \\
\hline
\end{tabular}
  \end{table}