\begin{table}%t3
%\centering
\par
\caption{\label{tab3}Spectral characteristics of the central \mbox{X-ray} sources within the supernova remnant \G.}
\small  \begin{tabular}{c c c c}
\hline\hline
Source&Net rate & $\Gamma$ &  $f_{x}$\\
{}& ($10^{-3}$ cts/s)& {} & (ergs~cm$^{-2}$ s$^{-1}$)\\
\hline \noalign{\smallskip}
9 &  $1.17\pm0.24$& $\rm 3.2^{+1.0}_{-0.8}$ & $2.8\times10^{-14}$\\ 
10 & $0.42\pm0.26$ & $\rm 2.7^{+2.4}_{-1.7}$  & $9.8\times10^{-15}$\\ 
11 & $2.54\pm0.39$   & $2.7\pm0.4$ & $4.5\times10^{-14}$\\ 
35 & $0.75\pm0.23$ & $\rm 1.3^{+0.7}_{-0.5}$ & $1.2\times10^{-14}$\\ 
 \hline
 \end{tabular}
 \end{table}