\begin{table}%t1
\par
\caption {\label{tab:sxmach}Best-fit parameters for the shocked surface brightness model in the four sectors.}
%\centerline
 {\begin{tabular}{lccccc}
\hline
\hline
Sector & Radius & $\eta$ & Mach & Shock energy & Shock age \\
 & (arcmin) & & number & ($10^{61}$~erg) & (Myr)\\
\hline
Np$^a$	    & 6.0 & 2.9 & $1.30\pm0.08 $ & $2.3\pm1.0$ & $230\pm30$\\
Ep           & 5.0 & 2.8 & $1.34\pm0.06 $ & $2.6\pm0.6$ &$170\pm16$\\ 
Sp     	    & 4.3 & 2.7 & $1.30\pm0.06$ & $2.0\pm0.7$ & $154\pm20$\\
Wp          & 4.0 & 2.7 & $1.33\pm0.06$ & $2.3\pm0.7$ & $132\pm16$\\ 
\hline
Nc$^b$  & 6.0 & 2.9 & $1.33\pm0.08 $ & $2.7\pm1.0$ & $215\pm30$\\
Ec         & 5.0 & 2.7 & $1.30\pm0.05 $ & $2.0\pm0.5$ &$180\pm16$\\ 
Sc    	    & 4.3 & 2.7 & $1.23\pm0.06$ & $1.4\pm0.6$ & $171\pm18$\\
Wc        & 4.0 & 2.7 & $1.25\pm0.06$ & $1.6\pm0.6$ & $151\pm18$\\ 
\hline
\end{tabular}}
\par
\smallskip
$^a$  {Annuli shape based on the pressure map.}
$^b$ {Annuli shape based on the Chandra image.}
\end{table}