\begin{table}%t3 %\centering \par \caption{\label{tab-fit-xmm}Results from the VPSHOCK+VPSHOCK model fits.} \begin{tabular}{lrrrr} \hline\hline\noalign{\smallskip} \multicolumn{1}{l}{Parameter} & \multicolumn{1}{c}{May 2003}& \multicolumn{1}{c}{Jan. 2007}& \multicolumn{1}{c}{Jan. 2008}& \multicolumn{1}{c}{Jan. 2009}\\ \noalign{\smallskip}\hline\noalign{\smallskip} \vspace{1mm} $kT_{1}$(keV) & $\rm 0.41_{-0.01}^{+0.01}$ & $\rm 0.52_{-0.003}^{+0.002}$ & $\rm 0.53_{-0.001}^{+0.002}$ & $\rm 0.54_{-0.001}^{+0.002}$\\ $kT_{2}$(keV) & $\rm 2.89_{-0.19}^{+0.19}$ & $\rm 2.43_{-0.06}^{+0.06}$ & $\rm 2.50_{-0.05}^{+0.05}$ & $\rm 2.38_{-0.05}^{+0.04}$ \\ \vspace{1mm} $EM_{1}$\tablefootmark{a} & $\rm 4.09_{-0.1}^{+0.1}$ & $\rm 17.83_{-0.12}^{+0.11}$ & $\rm 23.45_{-0.12}^{+0.13}$ & $\rm 28.37_{-0.14}^{+0.15}$ \\ \vspace{1mm} $EM_{2}$\tablefootmark{a} & $\rm 1.06_{-0.03}^{+0.03}$ & $\rm 2.95_{-0.05}^{+0.04}$ & $\rm 3.91_{-0.05}^{+0.06}$ & $\rm 4.91_{-0.07}^{+0.05}$ \\ \vspace{1mm} $\tau_{{\rm u,}1}$\tablefootmark{b} & $\rm 3.25_{-0.26}^{+0.29}$ & $\rm 4.82_{-0.12}^{+0.14}$ & $\rm 6.03_{-0.14}^{+0.19}$ & $\rm 6.86_{-0.18}^{+0.21}$ \\ \vspace{1mm} $\tau_{{\rm u,}2}$\tablefootmark{b} & $\rm 1.33_{-0.1}^{+0.12}$ & $\rm 1.93_{-0.1}^{+0.11}$ & $\rm 2.02_{-0.1}^{+0.09}$ & $\rm 2.22_{-0.09}^{+0.13}$ \\ \vspace{1mm} $\sigma_0$(eV) & $\rm 3.51_{-0.94}^{+1.11}$ & $\rm 1.51_{-0.4}^{+0.25}$ & $\rm 1.58_{-0.29}^{+0.31}$ & $\rm 1.43_{-0.29}^{+0.33}$ \\ \vspace{1mm} $\alpha$ & $\rm 1.10_{-0.76}^{+0.74}$ & $\rm 2.64_{-0.45}^{+0.69}$ & $\rm 3.15_{-0.63}^{+0.43}$ & $\rm 3.10_{-0.52}^{+0.6}$ \\ \hline \end{tabular} \tablefoot{Errors for $\Delta\chi^2=2.71$ confidence range.\\ \tablefoottext{a}{$EM = \int n_{\rm e} n_{\rm H} {\rm d}V$ in $10^{58}$~cm$^{-3}$, a distance of 50~kpc is assumed.}\\ \tablefoottext{b}{$\tau_{\rm u}$: upper limit on the ionization time range in $10^{11}$ cm$^{-3}$ s.}} \end{table}