\begin{table}%t1
      \caption{\label{tab:beams}Beam sizes and efficiencies. }
         \small %\centering
\par
         \begin{tabular}{lcccc}
            \hline\hline
            %\noalign{\smallskip}
            Molecule & Transition & $\nu$ & {\it HPBW} & $\eta_{\rm mb}$ \\
	             &  $J$/$N_J$ & [GHz] &    [$''$]       &       \\
              \hline
              CN & $2_{5/2}{-}1_{3/2}$  & 226.875 & 21 & 0.67 \\            
            CN & $3_{5/2}{-}2_{5/2}$  & 339.517 & 15 & 0.63 \\	    
	    HCN & $4{-}3$ &  354.505 & 14 & 0.63 \\
	    HCO$^+$ & $4{-}3$ &  356.734 & 14 & 0.63 \\
            HNC & $4{-}3$ &  362.630 & 14 & 0.63 \\	    
            %\noalign{\smallskip}
            \hline
         \end{tabular} 
  \end{table}