\begin{table}%t2
  \caption{Details for the molecular clouds towards the VHE sources in the W~28 field, assuming a distance $d$.}
  \label{tab:masses}
  \small%\centerline
{
    \begin{tabular}{llllll}
    \hline\hline\noalign{\smallskip}
      VHE Source        & $V_{\rm LSR}$   & $d$   & $^\dagger M$  & $^\ddagger n$  & $^\S k_{\rm CR}$ \\
      &   (km~s$^{-1}$) & (kpc) &      &      & \\ \hline 
      HESS~J1801$-$233  & 0--25  & 2.0 & 0.5 & 1.4 & 13 \\ 
      HESS~J1801$-$233  & 0--12  & 2.0 & 0.2 & 2.3 & 32 \\ 
      HESS~J1801$-$233  & 13--25 & 4.0 & 1.1 & 0.6 & 23 \\ 
      HESS~J1800$-$240  & 0--20  & 2.0 & 1.0 & 1.0 & 18 \\ 
      HESS~J1800$-$240A & 12--20 & 4.0 & 1.0 & 0.7 & 28 \\ 
      HESS~J1800$-$240B & 0--12  & 2.0 & 0.4 & 2.3 & 18 \\ 
      HESS~J1800$-$240B & 12--20 & 4.0 & 1.5 & 1.2 & 19 \\  
       \hline \end{tabular}}
     \smallskip
      $^\dagger$ Cloud mass $\times 10^5~M_\odot$. 
      $^\ddagger$ Cloud density $\times 10^3$~cm$^{-3}$. 
      $^\S$ Cosmic-ray density enhancement, $k_{\rm CR}$ above the local value required to 
      produce the $E>1$~TeV VHE $\gamma$-ray emission (using Eq.~(10) of  Aharonian \cite{Aharonian:1}).
\end{table}