\begin{table}%t3 %\centering \par \caption {\label{tab:pnspecall}The joint best-fit spectral parameter for the 2-$T$ fit with individually varying metal abundances for the 4 pn spectra. The notation ``$M/M_\odot$'' indicates the ratio between the \bcep\ coronal abundance and the solar photospheric abundance. The notation ``$M/M_{\rm phot}$'' indicates the ratio between the coronal abundance of \bcep\ determined here and the photospheric abundance of \bcep\ determined by \citet{mba+2006}. In all cases, the solar photospheric abundances of \citet{gs98} were used. The indicated uncertainties are~90\% errors derived from a $\Delta \chi^2$ analysis. For all heavy elements not explicitly indicated, the abundances are equal to the value for~Fe.} \begin{tabular}{cl} \hline\hline $N({\rm H})$ & $2.50 \pm 0.01 \times 10^{20}$ cm$^{-2}$\\ $T_1$ & $0.24\pm0.01 $ keV\\ $T_2$ & $0.63\pm0.03 $ keV\\ $E\!M_1$ & $1.1\pm0.2$ $10^{54}$ cm$^{-3}$ \\ $E\!M_2$ & $1.3\pm0.3$ $10^{53}$ cm$^{-3}$ \\ O/O$_\odot$ & $0.12\pm0.02 $\\ Ne/Ne$_\odot$ & $0.18\pm0.03$ \\ Si/Si$_\odot$ & $0.31\pm0.06 $\\ Fe/Fe$_\odot$ & $0.33\pm0.04$\\ O/O$_{\rm phot}$ & 0.28\\ Si/Si$_{\rm phot}$ & 0.86\\ Fe/Fe$_{\rm phot}$ & 0.60\\ \hline \end{tabular} \end{table}