\begin{table}%T5
\caption{\label{tab:joint1}Fit parameters of the joint optical and X-ray fit 
($\chi^2/\rm{d.o.f.}=62.11/65=0.96$).}
\small%\centerline
{
\begin{tabular}{ll}
\hline\hline
\multicolumn{2}{c}{\textbf{Before the jet break}}\\
Parameter                                 & Value\\
\hline
 $\alpha^{\rm opt} _R$               & $-0.70 \pm 0.15$\\
 $\alpha^{\rm opt} _1$               & $0.89  \pm 0.04$\\
 $t^{opt} _{\rm{b},~1}$ (days)      & $0.004\pm 0.0007$\\
 $n^{\rm opt} _1$	                 & 2.5\\
 $\alpha^{\rm X}_0$                  & $0.32 \pm 0.06$\\
 $\alpha^{\rm X}_1$                  & $1.54  \pm 0.11$\\
 $t^{X} _{\rm{b},~1}$ (days)        & $0.072 \pm 0.008$\\
 $n^{\rm X} _1$	                 & 10\\
%\hline
\multicolumn{2}{c}{\textbf{After the jet break}}\\
Parameter                                 & Value\\
%\midrule
 $\alpha _2$                         & $2.56 \pm 0.13$\\
      $t_{\rm{b},2}~\rm \left( days\right)$& $0.27 \pm 0.02$\\
      $n_2$                               & 10\\
\hline
\end{tabular}}
\smallskip
\end{table}