\begin{table}%t2
\caption{\label{tab:pow_law}Power-law fit to PACS differential number counts in the form ${\rm d}N/{\rm d}S\propto S^{\alpha}$.}
%\centering
\par
\begin{tabular}{l c c c}
\hline
\hline\noalign{\smallskip}
Field & Flux range  & Slope & Error \\
band  & $[$mJy$]$ & $\alpha$ & $d\alpha$\\
\hline
GOODS-N 100 & 2.8$-$5.6 & --1.32 & $\pm$0.27\\
GOODS-N 100 & 5.6$-$45 & --2.31 & $\pm$0.05\\
LH 100 & 6.0$-$89 & --2.60 & $\pm$0.05\\
COSMOS 100 & 8.0$-$142 & --2.63 & $\pm$0.03\\
\hline
GOODS-N 160 & 5.6$-$9.0 & --1.67 & $\pm$0.32\\
GOODS-N 160 & 9.0$-$71 & --2.54 & $\pm$0.04\\
LH 160 & 9.0$-$113 & --2.68 & $\pm$0.05\\
COSMOS 160 & 17.0$-$179 & --3.02 & $\pm$0.04\\
\hline
\end{tabular}\vspace*{-2.5mm}
\end{table}