\begin{table}%t2
\caption{\label{table:2}Summary of the statistical comparison of EPIC fluxes in different energy bands.} 
\small%\centerline
 {
\begin{tabular}{c c c c c c c c c c }         
\hline\hline                  
Energy band & & pn vs. MOS1 & & & pn vs. MOS2 & & & MOS2 vs. MOS1 \\
 (keV)  & $\mu$(\%) & $\sigma$ & $N_{{\rm srcs}}$ & $\mu$(\%) & $\sigma$ & $N_{{\rm srcs}}$ & $\mu$(\%) & $\sigma$ & $N_{{\rm srcs}}$ \\
\hline                         
      0.2--0.5   & $   -2.0\pm  0.5$ & $ 16.0\pm  0.5 $ &   909  & $  1.2\pm  0.4$ & $ 13.2\pm  0.4 $ &   885  & $ -0.9\pm  0.3$ & $  9.0\pm  0.4 $ &  1092    \\
        0.5--1.0   & $   -7.9\pm  0.1$ & $  8.2\pm  0.2 $ &  2132  & $ -8.2\pm  0.1$ & $  7.9\pm  0.2 $ &  2197  & $  1.0\pm  0.2$ & $  7.8\pm  0.3 $ &  2626    \\
          1.0--2.0   & $   -8.5\pm  0.2$ & $  7.5\pm  0.2 $ &  2721  & $ -9.1\pm  0.2$ & $  7.3\pm  0.2 $ &  2781  & $  0.3\pm  0.2$ & $  7.2\pm  0.2 $ &  3282    \\
        2.0--4.5   & $   -7.1\pm  0.2$ & $  7.1\pm  0.2 $ &  1527  & $ -6.5\pm  0.2$ & $  7.4\pm  0.2 $ &  1546  & $ -0.7\pm  0.2$ & $  7.1\pm  0.2 $ &  1769    \\
       4.5--12.0   & $  -12.5\pm  0.5$ & $  9.8\pm  0.5 $ &   484  & $ -9.0\pm  0.5$ & $  9.5\pm  0.5 $ &   502  & $ -3.8\pm  0.2$ & $  8.0\pm  0.2 $ &   549    \\
\hline                                    
\end{tabular}}
\medskip
$\mu$ and $\sigma$ are the $\chi^2$ best-fit mean and dispersion of the Gaussian distribution used to fit the data. $N_{{\rm srcs}}$~is the total number of sources involved in the analysis. Errors are 90\%~confidence.
\end{table}