\begin{table}%t3
      \caption{\label{spin_spectra}Spectral parameters as derived from  
fitting the EPIC PN spectrum at maximum and minimum of spin pulsation 
using Model~A in Table~\ref{spectra}.}
         \small
     %\centerline
{
\begin{tabular}{ c c c }
            \hline \hline
 & Pulse maximum & Pulse minimum \\
            \noalign{\smallskip}
            \hline
            \noalign{\smallskip}
$F_{2-10}$ & 1.90 $\pm$ 0.02 &  1.74 $\pm$ 0.03 \\ 
$\rm [10^{-12}~erg~cm^{-2}~s^{-1}]$  &    & \\
            \noalign{\smallskip}
            \hline
            \noalign{\smallskip}
$N_{\rm H}~[10^{23}$~cm$^{-2}]$   & $\rm 1.01^{+0.29}_{-0.34}$ & $\rm 1.33^{+0.41}_{-0.27}$    \\
$\rm Cov_{F}$ & $\rm 0.49^{+0.03}_{-0.02}$ & 0.56$\pm$0.03 \\
$kT_{\rm BB}$~[keV] &  $\rm 50^{+11}_{-10}$ & $\rm 51^{+\infty}_{-10}$ \\
$C_{\rm BB}~[10^{-5}]$ & $\rm 1.25^{+1.03}_{-0.75}$ & $\rm 1.13^{+1.07}_{-\infty}$ \\
$kT_{1}$~[keV] & $\rm 0.16^{+0.02}_{-0.04}$ & $\rm 0.17^{+0.04}_{-0.03}$ \\
$C_{1}~[10^{-4}]$ & $\rm 3.4^{+4.2}_{-1.4}$ & $\rm 3.0^{+11.6}_{-0.9}$ \\ 
$A_{\rm Z}^{a}$ & 0.39 & 0.39 \\
$kT_{2}^{a}$~[keV]  & 11 & 11 \\
$C_{2}^{a}~[10^{-4}]$ & 19.04 & 19.04 \\
$\chi^2_{\nu}$ ($\chi^2$/d.o.f.) & 0.90 (127/141) & 1.01 (111/110) \\
            \hline
\end{tabular}}
\smallskip
$^a$  Parameter fixed at the value found for the average spectrum.
\end{table}