\begin{table}%t2
   %%\centering

\par
      \caption{\label{sys}Systematic uncertainties of the cluster temperature measurement
      in the bin 7.5$'$--11.5$'$.} 
         \begin{tabular}{p{0.5\linewidth}c}
            \hline\hline
            Test & $\Delta k\tx$/[{keV}] \\
            \hline
            1 Particle background ($-$5\%)	& +0.18	\\
            2 Particle background ($+$5\%)	& --0.17	\\
            3 PSF (25\% contamination)	& --0.68	\\
            4 Foreground modeling (double thermal)	& +0.61	\\
            5 ROSAT foreground (thermal)	& +0.32	\\
            6 ROSAT background (powerlaw)	& +0.46	\\
            7 ARF from ROSAT surface brightness	& +0.01	\\
            8 Extrapolated cluster emission beyond $r_{200}$	& +0.24	\\
            \hline
         \end{tabular}
      \end{table}