\begin{table}%t4
%\centering
\caption{Best fit parameters to EPIC data using a 2~components MEKAL
  model (Mewe et~al. \cite{Mewe85}) with variable abundance and a variable
  hydrogen column density.\label{tab4}}
\begin{tabular}{ c  c  c }
\hline
\hline
 & Rev. 107 & Rev. 200 \\
\hline
 $Z$ & 0.32 $\pm$ 0.02 & 0.28 $\pm$ 0.03 \\
%\hline
 $kT_{\rm 1}$ (keV) & 0.73 $\pm$ 0.09 & 0.74 $\pm$ 0.01 \\ 
 $EM_{\rm 1}$ (10$^{52}$ cm$^{-3}$) & 62 $\pm$ 6 & 61 $\pm$ 9 \\ 
%\hline
 $kT_{\rm 2}$ (keV) & 2.10 $\pm$ 0.03 & 1.78 $\pm$ 0.04 \\ 
 $EM_{\rm 2}$ (10$^{52}$ cm$^{-3}$) & 258 $\pm$ 1 & 219  $\pm$ 7 \\ 
%\hline
 $\chi^{2}$ & 855/749 d.o.f. = 1.14 & 615/541 d.o.f. = 1.14 \\ 
\hline
\end{tabular}
\end{table}