\begin{table}%T2
\par
\caption{Fits of the {\it BeppoSAX} data using a power law plus Galactic absorption model: best 
fit spectral parameters.}\label{Tab2}
%\begin{center}
{
%\addtolength{\tabcolsep}{-2pt}
\begin{tabular}{lccc}
\hline
\hline
%\rule[-0.5em]{0pt}{1.6em}
Observation & $\Gamma$ & $N_{\rm H}$ & $\chi^2$(d.o.f.), proba.\\
\hline 
%\rule[-0.5em]{0pt}{1.6em}
& & $10^{20}$~cm$^{-2}$&\\
\hline 
2001 & $\rm 1.87^{+0.02} _{-0.03}$ & $<$3.15$^p$ &182.23(139), 0.008\\
1997 & $\rm 1.77^{+0.07} _{-0.06}$ & $<$4.08$^p$ &106.88(99), 0.277\\
2002 & $\rm 1.72^{+0.07} _{-0.07}$ & $\rm 3.69^{+2.75} _{-0.79}$ &104.70(99), 0.328\\
\hline
\end{tabular}}
$^p$ Pegged at Galactic value $N_{\rm H}=2.90\times10^{20}$~cm$^{-2}$. 
%\end{center}
\par
\end{table}