\begin{table}%T1
%\centering
\par
\caption{Present-day masses and virial radii for the three most
  massive and the three least massive haloes in our sample.}
\label{tab:1}
\begin{tabular}{lrr}
\hline\hline
Halo Id. & Virial mass & Virial radius\\
 & [$h^{-1}~M_\odot$] & [$h^{-1}~{\rm Mpc}$]\\
\hline
g8-a & $2.289 \times 10^{15}$ & 2.146 \\
g1-a & $1.530 \times10^{15}$ & 1.876 \\
g72-a & $1.374 \times10^{15}$ & 1.810 \\
\hline
g696-y & $5.219\times 10^{13}$ & 0.608\\
g696-z & $5.171\times 10^{13}$ & 0.607\\
g696-\# & $5.060\times 10^{13}$ & 0.602\\
\hline
\end{tabular}
\end{table}