\begin{table}%t4
\caption{Mean values  and standard deviation  of  spectral parameters~$\beta_1$, $\beta_2$ and $\log\epc$  for  the  parent distribution   of XRRs/XRFs and GRBs classes, according to the likelihood method. In the last row is  the $\log\epc$ instrinsic mean value for the subsample of events used  for the X-ray afterglow flux analysis in Sect.~\ref{sec:results}.}
 \label{tab10}
%\centering
\small
  \begin{tabular}{rcc|ccc}
   \hline \hline
     CLASS(number)&$\langle\beta_1\rangle_i$&$\langle\sigma\rangle_i$ &CLASS(number)& $\langle\beta_2\rangle_i$ &$\langle\sigma\rangle_i$\\
   \hline
     XRRs+XRFs (38) & $\rm -(1.22^{+0.12}_{-0.09})$ & $\rm 0.21^{+0.12}_{-0.09}$ & XRRs+XRFs (25) & $-$(1.74 $\pm$ 0.42) & $\rm 1.17^{+0.42}_{-0.28}$ \\
     GRB (31)      & $-(0.99^{+0.08}_{-0.10}$) & $\rm 0.28^{+0.06}_{-0.05}$  & GRB (19)      & $-(2.31^{+0.20}_{-0.16})$  & $\rm 0.46^{+0.20}_{-0.15}$   \\
   \hline
     CLASS (number)     & $\langle {\rm Log}~ E_{\rm peak}\rangle_i$ & $\langle\sigma\rangle_i$ &CLASS(number)& $\langle\tilde{{\rm Log}~ E}_{\rm p}\rangle_i$ &$\langle\sigma\rangle_i$\\
   \hline
     XRRs+XRFs (42) & 1.55 $\pm$ 0.1   &  0.32 $\pm$ 0.10    &XRRs+XRFs(10)  &$2.13\pm0.11$ & $0.17^{+0.16}_{-0.12}$ \\
     GRB (30)      & $2.21^{+0.06}_{-0.07}$   & $\rm 0.25^{+0.08}_{-0.05}$ &GRBs(12) &$2.74^{+0.14}_{-0.16}$ &$0.32^{+0.16}_{-0.09}$  \\
   \hline
     SUBCLASS (number)     & $\langle {\rm Log}~ E_{\rm peak}\rangle_i$ &   & &   & \\
   \hline
     XRRs+XRFs (7) & 1.83 $\pm$ 0.06   &  &  &  &  \\
     GRB (14)      & $2.32\pm0.10$   &  &  & & \\
   \hline
 \end{tabular}
\end{table}