\begin{table}%t2
 \caption{\label{table3b} Results reported from previous
analysis of X-ray afterglows detected by BeppoSAX. In this table, we
indicate the temporal decay, the energy index, the fitted value of~$n_{\rm H}$ compared to the galactic column density and the associated
reference. A label "W'' close to the decay index indicates that this
value was obtained by means of WFC and NFI data.}
\small%\centerline
{
\begin{tabular}{cccccc}
\hline\hline
 GRB~               & Temporal               & Energy             & $n_{\rm H}$ /$n_{\rm H}^G$              & 2--10 keV flux          & Ref. \\
 name               & index$^a$              & index              &                             &  at 10$^5$ s   $^{a}$   &  \\
                    &$\delta$                &$\alpha$            & ($\times10^{21}$ cm$^{-1}$) & (erg cm$^{-2}$s$^{-1}$) &  \\
\hline
\object{GRB~970111} & $\rm >$1.5                 & --                & --                         & $\rm <$$1.0\times10^{-13}$    & \citet{fer98}\\
\object{GRB~970228} & 1.3 $\pm$ 0.2          & 1.1 $\pm$ 0.3        & $\rm 3.5_{-2.3}^{+3.3}$ / 1.6   & $\rm \sim$$6.8\times10^{-13}$ & \citet{cos97,fro98}\\
\object{GRB~970402} & $\rm 1.45 \pm 0.15$        & 1.7 $\pm$ 0.6        & $\rm <$20 / 2.0                 & $\rm \sim$$4.5\times10^{-14}$ & \citet{nic98v}\\
\object{GRB~970508} & 1.1 $\pm$ 0.1$^b$        & 0.5 $\pm$ 0.55       & $\rm 6.0_{-3.3}^{+7.9}$ / 0.5   & $\rm 3.5\times10^{-13}$     & \citet{piro98b,piro99}\\
\object{GRB~971214} & $\rm \sim$$1.2$              & 0.6 $\pm$ 0.2        & $\rm 1.0_{-1.0}^{+2.3}$ / 0.6   & --                     & \citet{dal00}\\
\object{GRB~971227} & $\rm 1.12^{+0.08}_{-0.05}$(W) & [1.1]              & [0.13] / 0.13               & $\rm \sim$$1.4\times10^{-13}$ & \citet{ant99}\\
\object{GRB~980329} & 1.3 $\pm$ 0.03 (W)       & 1.4 $\pm$ 0.4        & 10 $\pm$ 4 / 0.9              &  $2.0\times10^{-13}$    & \citet{zan98}\\
\object{GRB~980425} & 0.16 $\pm$ 0.04          & 1.0 $\pm$ 0.18       & [0.39] / 0.39               & $\rm \sim$$4.0\times10^{-13}$ & \citet{pia00}\\
\object{GRB~980519} & 1.83 $\pm$ 0.30          & $\rm 1.8^{+0.6}_{-0.5}$& 3--20 / 1.73                & $\rm 8.0\times10^{-14}$     & \citet{nic98}\\
\object{GRB~980613} & 1.19 $\pm$ 0.17(W)       & ---               & --                         & $\rm \sim$$2.3\times10^{-13}$ & \citet{sof02}\\
\object{GRB~980703} & $\rm >$0.91                & 1.51 $\pm$ 0.32      &$\rm 36_{-13}^{+22}$$^{\rm c}$ / 0.34  & $\rm 4.5\times10^{-13}$     &\citet{vre99} \\
\object{GRB~981226} & 1.3$^{+0.5}_{-0.4}$    & 0.92 $\pm$ 0.47      & [0.18] / 0.18 &  $\sim$$2.0\times10^{-13}$& \citet{fro00b}\\
\object{GRB~990123}$^d$ & 1.46 $\pm$ 0.04  & 0.94 $\pm$ 0.08 & $\rm 0.9^{+15} _{0.9}$ / 0.21   & $\rm 1.25\times10^{-12}$    & \citet{mai05}\\
\object{GRB~990510} & 1.42 $\pm$ 0.07          & 1.03 $\pm$ 0.08      & 2.1 $\pm$ 0.6/0.94            & $\rm 9.6\times10^{-13}$     & \citet{kuu00}\\
\object{GRB~990704} & 0.83 $\pm$ 0.16          & $\rm 0.7^{+0.4}_{-0.2}$& [0.3] / 0.3                 & $\rm \sim$$3.3\times10^{-13}$ & \citet{fer01}\\
\object{GRB~990705} & 1.58 $\pm$ 0.06          & --                & --                           & $\rm <$$1.2\times10^{-13}$    & \citet{fro05}\\
\object{GRB~990806} & 1.15 $\pm$ 0.03(W)       &$\rm 1.16^{+0.3}_{-0.37}$ & [0.35] / 0.35            & $\rm \sim$$2.0\times10^{-13}$ & \citet{mon01}\\
\object{GRB~991014} & $\rm >$0.4                 & 0.53 $\pm$ 0.25      & [2.5]/ 2.5                  & $\rm \sim$$3.0\times10^{-13}$ & \citet{zan00b}\\
\object{GRB~000210} & $\rm 1.38\pm0.03$(W)       & $\rm 0.75\pm0.3$       & $\rm <$$4\times10^{21}$           & $\rm \sim$$2\times 10^{-13}$  &\citet{piro02}\\
\object{GRB~000214} & 0.8 $\pm$ 0.3            & 1.0 $\pm$ 0.18       &$\rm 0.7_{-0.7}^{+7.5}$/ 0.55   & $\rm \sim$$3.5\times10^{-13}$ & \citet{ant00} \\
\object{GRB~000926} & $1.89^{+0.16 e}_{\rm -0.19}$& $\rm 0.9\pm0.42$ &4/0.27$^e,^f$                      & $\rm 9.0\times10^{-13}$     & \citet{piro01}\\
\object{GRB~001109} & 1.18 $\pm$ 0.05          & 1.4 $\pm$ 0.3        & 8.7 $\pm$ 0.4$ /0.42$         & $\rm \sim$$8.0\times10^{-13}$ & \citet{ama02b}\\
\object{GRB~010214} &  $\rm 2.1^{+0.6}_{-1.0}$   &$\rm 0.3^{+0.8}_{-0.6}$ & [0.27] / 0.27               & --                     & \citet{gui03}\\
\object{GRB~010222} & 1.33 $\pm$ 0.04          & 0.97 $\pm$ 0.05      & 1.5 $\pm$ 0.3/ 0.16 & $\rm 2.4\times10^{-12}$ & \citet{zan01}\\
\object{GRB~011121} & $\rm 1.29\pm0.03$(W)       & $\rm 1.6\pm0.5$        & $\rm <$$100/$                     & $\rm \sim$$ 10^{-13}$         & \citet{piro05}\\
\object{GRB~020321} & --                    & --                &   --                       & $\rm <$$3\times10^{-13}$      & \citet{zand03}\\
\object{GRB~020410} & $\rm 0.81\pm0.07$          & $\rm 1.05\pm0.08$      &      --                    & $\rm \sim$$3.5\times10^{-12}$ & \citet{nic04}\\
\object{GRB~020427} & $\rm 1.3^{+0.13} _{0.09}$  & $\rm 1^{+2.2} _{-1.1}$ &  0.29/0.29                  & $\rm \sim$$10^{-13}$          & \citet{ama04}\\
\hline
\end{tabular}}
\smallskip
$^a$ All upper limits are 3$\sigma$, except for GRB~990705, which are 2$\sigma$. 
$^b$~From $6 \times 10^{4}$~s to~$5.8 \times 10^{5}$~s.
$^c$~$n_{\rm H}$~value corrected for redshift. 
$^d$~Spectral data of the first~20~000~s. The time decaying index includes the whole NFI TOO.
$^e$~\emph{SAX} plus \emph{CHANDRA} data \citep{piro01}. 
$^f$~Corrected for redshift \citep{piro01}. This~$n_{\rm H}^z$~value was added to the Galactic column density~$n_{\rm H}^G$.
\end{table}