\begin{table}%t2
%\centering
\par
\caption{ The threshold impact parameters $\langle u_{\rm T} \rangle
_{\phi}$ and $\langle u_{\rm T}^{~2} \rangle _{\phi}$ averaged over the
whole M~31 galaxy are given for different values of the superpixel
dimension $N \times N$, sky background $m_{\rm sky}$, fraction
$f_{\rm see}$ of the superpixel covered by the PSF and superpixel
flux stability $\sigma_{\rm T}$. \label{table00}}
\begin{tabular}{cccccc}
\hline\hline
$N \times N$ &$m_{\rm sky}$&$f_{\rm see}$&
$\sigma_{\rm T}$&$\langle u_{\rm T} \rangle _{\phi}$&$\langle u_{\rm T}^{~2} \rangle _{\phi}$ \\
             & (mag arcsec$^{-2}$)       &          &                  &  &\\
\hline
\noalign{\smallskip}
$3 \times 3$ &20.9&0.87&$2.5\times 10^{-3}$ N$_{\rm bl}$ &$1.10\times 10^{-1}$&$3.17\times 10^{-2}$\\
%\hline
$5 \times 5$ &20.9&0.87&$2.5\times 10^{-3}$ N$_{\rm bl}$ &$7.11\times 10^{-2}$&$1.59\times 10^{-2}$\\
%\hline
$7 \times 7$ &20.9&0.87&$2.5\times 10^{-3}$ N$_{\rm bl}$ &$5.10\times 10^{-2}$&$9.56\times 10^{-3}$\\
%\hline
$7 \times 7$ &20.9&0.40&$2.5\times 10^{-3}$ N$_{\rm bl}$ &$2.57\times 10^{-2}$&$3.13\times 10^{-3}$\\
%\hline
$7 \times 7$ &19.5&0.40&$2.5\times 10^{-3}$ N$_{\rm bl}$ &$1.44\times 10^{-2}$&$1.17\times 10^{-3}$\\
%\hline
$7 \times 7$ &19.5&0.40&$1.0\times 10^{-2}$ N$_{\rm bl}$ &$3.82\times 10^{-3}$&$1.23\times 10^{-4}$\\
\hline
\end{tabular}
\end{table}