\begin{table}%t2
%\centering
\par
\caption{Best-fit continuum parameters when the RGS1, RGS2, pn,
MOS1 and MOS2 \src\ spectra were fit simultaneously. {\em
dbb}~=~disk-blackbody, {\em pow}~=~power-law, {\em ctt}~=~Comptonization
model {\sc comptt} in {\sc xspec}. 
$\alpha$ is the
power-law photon index, $kT_{\rm in}$ the inner disk temperature,
$r{\rm _{in}}(\cos i)^{0.5}$ is the inner disk radius for a
distance of 8~kpc, $i$ is the disk inclination angle and $R{\rm
_{bb}}$ is the blackbody radius. For the {\sc comptt} model,
$kT{\rm _0}$ is the temperature of the "seed'' photons, $kT{\rm
_e}$ is the electron temperature (fixed at 70~keV) and ${\rm
\tau_p}$ is the plasma optical depth.\label{tab:spec}}
\begin{tabular}[c]{lclllllllr}
\hline\hline\noalign{\smallskip} Model  &\mc{1}{c}{$N{\rm _H}$}
&\mc{1}{c}{$\alpha$} &\mc{1}{c}{$kT{\rm _{in}}$} &\mc{1}{c}{$r{\rm
_{in}} (\cos i)^{0.5}$} &\mc{1}{c}{$kT{\rm _{bb}}$}
&\mc{1}{c}{$R{\rm _{bb}}$} &\mc{1}{c}{$kT{\rm _0}$}
&\mc{1}{c}{${\rm \tau_p}$}
& $\chi^2$/d.o.f. \\
  &($10^{21}$~cm$^{-2}$)&   &\mc{1}{c}{(keV)} &\mc{1}{c}{(km)}
&\mc{1}{c}{(keV)} &\mc{1}{c}{(km)}
&\mc{1}{c}{(keV)} & &  \\
\hline
\mc{3}{l}{Observation 1}    & & &  & & & &   \\
dbb+pow        & $\rm 5.7 ^{+0.3}_{-0.2}$ & $\rm 2.03^{+0.06}_{-0.06}$   & $\rm 0.69^{+0.02}_{-0.02}$  & $\rm 2.9^{+0.2}_{-0.2}$  &\dots & \dots & \dots & \dots  & 1.34/1092 \\
bb+pow            & $\rm 6.1^{+0.2}_{-0.2} $          & $\rm 2.18^{+0.04}_{-0.04}$    & \dots                          & \dots              & $\rm 0.48^{+0.02}_{-0.02}$ & $\rm 5.1 ^{+0.6}_{-0.6} $& \dots& \dots&  1.37/1092 \\
dbb+ctt    & $\rm 4.1^{+0.1}_{-0.1}$   & \dots & $\rm 0.73  ^{+0.03}_{-0.02}$& $\rm 2.5  ^{+0.3}_{-0.2}$& \dots& \dots& $\rm 0.23^{+0.01} _{-0.03}$&$\rm 1.2^{+0.1}_{-0.1}$ &  1.30/1091 \\
\hline
\mc{3}{l}{Observation 2}  & & & & & & &   \\
dbb+pow        & $\rm 5.7^{+0.2}_{-0.3}$ & $\rm 2.16  ^{+0.06}_{-0.06}$   & $\rm 0.75^{+0.06} _{-0.04}$ & $\rm 1.8  ^{+0.4}_{-0.4}$  & \dots & \dots &  \dots & \dots   & 1.43/963 \\
bb+pow            & $\rm 5.9^{+0.2}_{-0.2}$        & $\rm 2.24 ^{+0.04}_{-0.04}$   & \dots                     & \dots              & $\rm 0.55^{+0.07}_{-0.04}$ & $\rm 2.7 ^{+1.0}_{-0.7}$ & \dots &  \dots &  1.44/963 \\
dbb+ctt     & $\rm 3.6^{+0.2}_{-0.5}$ & \dots  & $\rm 0.84^{+0.10} _{-0.05}$ & $\rm 1.5 ^{+0.4}_{-0.4}$ & \dots& \dots& $\rm 0.22^{+0.03} _{-0.02}$ &  $\rm 1.0^{+0.1} _{-0.1}$&  1.38/962 \\
\hline
\end{tabular}
\end{table}