\begin{table}%t4
\caption{\label{tab4}Spectral analysis results.}
%\centerline
{
\begin{tabular}{l c c c c  c c c}
\hline
\hline
Name   & $\Gamma$ & $N_{\rm H}$ & $\chi^2_{\nu}$/d.o.f. & $P$ & $f_{0.5{-}2~\rm keV}$ & $f_{2{-}10~\rm keV}$ & $L_{2{-}10~\rm keV}$ \\
     &   & 10$^{20}$ cm$^{-2}$ & & \%  & 10$^{-13}$ erg cm$^{-2}$ s$^{-1}$ & 10$^{-13}$ erg cm$^{-2}$ s$^{-1}$ & 10$^{44}$ erg s$^{-1}$ \\
\hline
NEP~1239 & $\rm 1.76^{+0.10}_{-0.10}$ & $<$9 & 1.03/51 & 40 & $0.61\pm 0.1$ & $1.01\pm 0.1$ & $3.1\pm 0.3$ \\
 NEP~1640 & $\rm 1.88^{+0.09}_{-0.09}$ & $3{-}12$ & 0.88/72 & 75 & $0.82\pm 0.1$ & $1.14\pm 0.2$ & $2.2\pm 0.2$ \\
     NEP~2131 & $\rm 1.50^{+0.06}_{-0.06}$ & $<$$2 $ & 1.02/143 & 41 & $1.39\pm 0.1$ & $3.4\pm 0.3$ & $1.3\pm 0.1$ \\
\hline 
\end{tabular}}
\smallskip
Unabsorbed fluxes and rest-frame K-corrected luminosities; $N_{\rm H}$ is
the range of total absorption at the quasar redshift, 
when left free to vary. $P$~is the null hypothesis probability.
\end{table}