\begin{table}%t1
%\centering
\par
  \caption{The values of the black hole masses and rotational parameters used in the 
   calculations.\label{tab1}}
  \begin{tabular}{llrrrrl}
 \hline\hline
   $M/ 10^{7} M_{\odot}$ & 0.05 & 0.1 & 0.25 & 0.5 & 1 & 2\\  
   $M/ 10^{7} M_{\odot}$ & 4 & 8 & 16 & 32 & 64 & 100  \\
   $a$ & 0 & 0.25 & 0.5 & 0.75 & 0.9 & 0.9999 \\ 
\hline
\end{tabular}
\end{table}