\begin{table}%T1
\caption{Best-fit spectral parameters for the phase-resolved spectroscopy of \RX, in the case of the independent fit of the four spectra. Errors are at a 90\% confidence level for a single interesting parameter. $N_{\rm H}$ and $kT_{\rm BB}$ are measured in units of $10^{21}$~cm$^{-2}$ and~keV, respectively.}\label{4spectra_fit}
%\centerline
{\small
\begin{tabular}{c|cccc} \hline\hline
Spectral &   \multicolumn{4}{c}{Phase Interval}                                          \\
Parameter &   A           &   B           &   C           &   D           \\ \hline
$N_{\rm H}$&   $\rm 4.8^{+0.4}_{-0.7}$ &   $\rm 5.4^{+0.4}_{-0.3}$ &   $\rm 5.0^{+0.8}_{-0.7}$ &   $\rm 3.6^{+0.6}_{-0.5}$ \\
$\Gamma$           &   $\rm 1.47^{+0.19}_{-0.20}$  &   $\rm 1.39^{+0.09}_{-0.08}$  &   $\rm 1.31^{+0.35}_{-0.23}$  &   $\rm 1.06^{+0.11}_{-0.21}$  \\
$kT_{\rm BB}$         &   $0\rm .98^{+0.08}_{-0.12}$  &   $\rm 1.05^{+0.10}_{-0.08}$  &   $\rm 1.34^{+0.17}_{-0.18}$  &   $\rm 1.21^{+0.21}_{-0.16}$  \\ \hline
$f_{\rm TOT}^{a}$       &   1.81        &   3.22        &   1.74        &   1.00        \\
$f_{\rm PL}^{a}$        &   1.34    &   2.52    &   1.10    &   0.70     \\
 & (74\%) & (78\%) & (63\%) & (70\%) \\
$f_{\rm BB}^{a}$        &   0.47    &   0.70    &   0.64    &   0.30     \\
 & (26\%) & (22\%) & (37\%) & (30\%) \\ \hline
$\chi^{2}_{\nu}$/d.o.f.     &   0.972/308       &   1.021/992       &   1.085/352       &   1.131/328       \\ \hline
\end{tabular}}
\medskip
$^{a}$ Unabsorbed flux in the energy range 0.3$-$10~keV, in units of $10^{-11}$~erg~cm$^{-2}$~s$^{-1}$.
\end{table}