\begin{table}%t2
\caption{Distance and BH mass estimates.}\label{tab:objdata}
%\centerline
 {\small \begin{tabular}{lccc}
\noalign{\smallskip} \hline \hline\noalign{\smallskip}
Object & Distance$^{a}$ & $M_{\rm{BH}}$ & Ref.$^{b}$ \\
       & (Mpc)          & ($M_\odot$)   & \\
\noalign{\smallskip} \hline \noalign{\smallskip}
NGC~4235 & 38.0 &  $4.8\times10^7$ & (1)  \\
 NGC~4639 & $18.4$ & $7.1\times10^6$ & (2)  \\
NGC~5033 & $15.2$ & $2.8\times10^7$ & (3)  \\
NGC~5273 & $17.5$ & $1.6\times10^6$ & (4)  \\
\hline
\end{tabular}}
\medskip
$^{a}$ Luminosity distances from NED; $^{b}$ references for the black hole masses: (1)~Dong \& de Robertis (\cite{Dong2006});  (2)~Panessa \etal\ (\cite{Panessa2006}); (3) Chiaberge \etal\ (\cite{Chiaberge2005}); (4)~Wu \& Han (\cite{Wu2001}).
\end{table}