\begin{table}%t2
%\centering
\par
\caption {Galaxy luminosity function in four bands: power-law fits on
global image.\label{tab:LF}}
\begin{tabular}{lccccc}
\hline\hline
Filter & $u^*$ & $g'$ & $r'$ & $i'$ \\ 
\hline
Magnitude range &
$20.5\leq u^*     \leq23.0$ &
$19.0\leq g'\leq23.0$ & 
$18.5\leq r'\leq23.0$ &
$18.0\leq i'\leq22.5$ \\
$\alpha\pm 1\sigma$ &
    $-1.70\pm0.48$ &
    $-1.46\pm0.15$ &
    $-1.52\pm0.12$ &
    $-1.45\pm0.11$ \\ 
\hline
\end{tabular}
\end{table}