\begin{table}%t2
\caption{\label{tab:abund}Best-fit parameters.}
\par
\small%\centerline
 {
\begin{tabular}{lcc} 
\hline\hline
            Element                 &     Region NW$^*$   &  Region SE$^{**}$   \\ \hline
          $\rm{O/O}_\odot$               &    $5.0\pm0.1$      &    $4.4\pm0.3$      \\
          $\rm{Ne/Ne}_\odot$             & $\rm 4.7^{+0.1}_{-0.2}$ & $\rm 1.5^{+0.2}_{-0.1}$ \\
       $\rm{Mg/Mg}_\odot$                &   $12\pm2$          &    $15\pm1$         \\
       $\rm{Si/Si}_\odot$                &  $\rm 29^{+3}_{-2}$     &       $50\pm3$        \\[2pt] 
       \hline
%&&&&& \\[-8pt]
  $kT$ (keV)                  &  $0.41\pm0.03$      &  $\rm 0.68^{+0.09}_{-0.04}$     \\
 $EM^{***}$ ($10^{17}$ cm$^{-5}$ )  &  $1.6\pm 0.1 $      &  $\rm 1.53_{-0.05}^{+0.12}$    \\
$\tau_{PS}$ ($10^{10}$ s cm$^{-3}$) &  $1.6\pm0.2$        &  $\rm 1.3^{+0.2}_{-0.3}$       \\   
   reduced  $\chi^2$ (d.~o.~f.)     &  $1.85$ $(426)$    &   $1.84$ $(234)$           \\   
\hline
\end{tabular}}
\medskip
* Union of regions 13$-$16 of Fig.~\ref{fig:softhard};
**~union of regions~28, 29, 0, and~1 of Fig.~\ref{fig:softhard};
***~emission measure per unit area.
\end{table}