\begin{table}%t6
\caption{Black hole mass solutions for $T_{\rm o} = 480$~yr.}
\label{tb:sol-mass}
%\centerline
{
\begin{tabular}{c|ccccc}\hline\hline
Parameter & \multicolumn{5}{c}{Value} \\\hline
$M_1$ $[10^8~M_{\odot}]$ & 2.0 & 6.0 & 7.1 & 20.0 & 60.0 \\
$M_2$ $[10^8~M_{\odot}]$ & 4.0 & 6.6 & 7.1 & 12.3 & 23.1 \\
$r_{\rm o}$ $[{\rm pc}]$ & 0.25 & 0.32 & 0.33 & 0.44 & 0.60 \\ 
$T_{{\rm disk}}$ $[{\rm yr}]$ & 179 & 229 & 239 & 314 & 430 \\ 
\hline
\end{tabular}}
\medskip
Notes: $r_{\rm o}$~--~orbital separation between the black holes,
$T_{{\rm disk}}$~--~characteristic rotational period of the accretion
disk around the primary black hole.
\end{table}