\begin{table}%t3
\caption{\label{t:hybrid}Best-fit parameters of the multi-component model\protect  \wabs(\bb\ + \eqpair\ + \gaussian) for the first and second observation of \mbox{GX 17+2}.
The F-test gives the probability of chance improvement of the \chiq\ switching from thermal to hybrid Comptonization.  The compactness parameters \ls, \lh\  and \lnth\  are  defined in Sect.~\ref{eqpair}. The ratio $L_{\rm bb}/L_{\rm tot}$ is computed in the energy range 0.4$-$200~keV.}
%\centerline
{
\begin{tabular}{ccc}
\hline
\hline
Parameter          & Obs. 1		   &	Obs. 2\\
                   & I		   &	II+III+IV\\
\hline
$N_{\rm H}^{\rm a}$ &   $\rm 2.00^{+0.05}_{-0.05}$ & $\rm 1.97^{+0.07}_{-0.06}$  \\
$kT_{\rm bb}$ (keV) &   $\rm 0.58^{+0.02}_{-0.01}$  &  $\rm 0.60^{+0.01}_{-0.02}$     \\
$R_{\rm bb}$ (km) & $\rm 33^{+2}_{-2}$ &  $\rm 31^{+3}_{-3}$   \\
$kT_{\rm s}$ (keV) &   $\rm 0.88^{+0.14}_{-0.08}$ &   $\rm 0.95^{+0.03}_{-0.05}$  \\
$kT_{\rm e}$ (keV) &  3.5  & 3.5    \\
$\ell_{\rm s}$  & $\rm 7600^{+7000}_{-3400}$ &  [7600] \\ 
$\ell_{\rm h}/\ell_{\rm s}$   & $\rm 0.87^{+0.02}_{-0.02}$ & $\rm 0.63^{+0.01}_{-0.03}$    \\ 
$\ell_{\rm nth}/\ell_{\rm h}$ & $\rm 0.11^{+0.02}_{-0.02}$ &  $<$$0.04$ \\ 
$\tau$ &  $\rm 8.4^{+1.5}_{-0.7}$  & $\rm 8.4^{+0.1}_{-0.2}$     \\
$p $  & $\rm 1.7^{+1.1}_{-0.6}$ &  [1.7]\\
$\gmin $  &  $\rm 1.15^{+1.54}_{-0.15}$   & [1.15] \\
$\gmax $  & [12] & [12] \\
F-test & $ 4 \times 10^{-11}$  &  0.07    \\
\hline
$E_{\rm l}$ (keV) & $\rm 6.7^{+0.1}_{-0.1}$ & $\rm 6.7^{+0.1}_{-0.1}$   \\
$\sigma_{\rm l}$ (keV) &   $\rm 0.2^{+0.1}_{-0.1}$    & $\rm 0.2^{+0.1}_{-0.1}$   \\
$I_{\rm l}^{b}$ &  $\rm 4.4^{+1.3}_{-0.8}$  & $\rm 4.8^{+2.2}_{-0.8}$    \\
$EW_{\rm l}$ (eV)  &   $\rm 32^{+9}_{-6} $ & $\rm 33^{+15}_{-6} $     \\
\hline
$L_{\rm bb}/L_{\rm tot}$ & 0.11 &  0.11  \\
$L_{~0.4-30~{\rm~keV}}^{\rm c}$ & 1.44 & 1.46 \\
$L_{~30-200~{\rm~keV}}^{\rm c}$ & 0.019 &  0.006 \\
${\chi^{2}}$/d.o.f. & 143/142 &  185/141   \\
\hline
\end{tabular}}
\smallskip
$^{\rm a}$ In units of 10$^{22}$ cm$^{-2}$.  \\
$^{\rm b}$ Total photons in the line in units of 10$^{-3}$ \cmdeux\ \sune.  \\
$^{\rm c}$ Unabsorbed luminosity in units of 10$^{38}$ erg s$^{-1}$. \\
\end{table}