\begin{table}%t4
  \caption{\label{tab:ps}EPIC-CS measurement for three point sources cases.}
  %\centering
\par
  $$
  \begin{array}{ccccccc}
    \hline
    \hline
      r & r^{\rm no-ps} & r^{\rm ideal} & r^{\rm no-model} & \sigma_r^{\rm no-ps} & \sigma_r^{\rm ideal} & \sigma_r^{\rm no-model} \\
      \hline
       0.001 & 1.07 \times 10^{-3} & 1.04 \times 10^{-3} & 2.00 \times 10^{-3} & 1.84 \times 10^{-4} & 1.91 \times 10^{-4} & 2.49 \times 10^{-4} \\
       \hline
  \end{array}
  $$
\end{table}