\begin{table}%t2
\caption{\label{tab_mod} Continuum spectral model for XMM-Newton and RXTE observations.}
%\centerline
 {\begin{tabular}{ c c c c c }
\hline \hline
\noalign{\smallskip}
Parameters & 27 Feb. 2005 & 14 March 2005 & 15 March 2005 & 16 March 2005 \\
\noalign{\smallskip}
\hline
\noalign{\smallskip}
$N_{\rm {H}} (\times 10^{21})$ cm$^{-2}$& $5.2\pm0.2$ 	& 5.46~$\pm$~0.02	   & 5.57~$\pm$~0.02 	& 5.45~$\pm$~0.03\\
Dust fraction$^{{a}}$ 		& 0.15~$\pm$~0.03 & 0.186~$\pm$~0.002  & 0.169~$\pm$~0.003 	& 0.184~$\pm$~0.003\\
$kT_{\rm in}$ (keV)				&     --		& 1.231~$\pm$~0.003  & 1.268~$\pm$~0.003 	& 1.326~$\pm$~0.003 \\
$R_{\rm in}^{{b}}$ (km) 				&     --		& 14.25~$\pm$~0.05   & 13.25~$\pm$~0.05 	& 13.55~$\pm$~0.05 \\
$\Gamma$ 				& 1.48~$\pm$~0.01 & 2.10~$\pm$~0.01    & 2.27~$\pm$~0.01 	& 2.13~$\pm$~0.01\\
$K^{{c}}$ (ph~keV$^{-1}$~cm$^{-2}$~s$^{-1}$@ 1~keV)& 0.0385~$\pm$~0.0007 & 0.94~$\pm$~0.02 & 0.76~$\pm$~0.07   	& 1.05~$\pm$~0.02 \\
$L_{~0.4{-}10~\rm{keV}} ^{{d}}$ (erg~s$^{-1}$)&$3.7\times10^{35}$&$3.4\times10^{37}$&$3.4\times10^{37}$&$4.2\times10^{37}$ \\
\hline
\end{tabular}}
\par
\smallskip
$^{{a}}$  Dust scattering fraction at 1~keV. 
Halo size is fixed to 10~times the detector beam-size at 1~keV.
$^{{b}}$  For a distance of 3.2~kpc and an inclination of~70$\degr$.
$^{{c}}$  Normalization constant for the power law component.
$^{{d}}$  Luminosity in the range 0.4--10~keV, for a distance of 3.2~kpc.
\end{table}