\begin{table}%t1
    \caption{Observation parameters. The projection center of all the data 
      matches the position of NRAO150: $\rm \alpha_{2000} = 03^h59^m29.747^s$, 
      $\delta_{2000} = 50\deg57'50.16''$.}
    \small%\centerline
{
    \begin{tabular}{rcrllccccccr}
          \hline \hline\noalign{\smallskip}
          Molecule & Transition & Frequency  & Instrument & Config. & Beam   & PA     & Vel. resol. & Int. time & $T_{\rm sys}$  & Noise$^{a}$ & \multicolumn{1}{c}{Obs. date} \\
                   &            & GHz        &            &         & arcsec & $\deg$ & \kms{}      & h      & K       & K           & \\
          \hline\noalign{\smallskip}
          \twCO{} & \Jone{} & 115.271202 & PdBI & D & $ 6.0 \times 5.5$ & 82 & 0.2 & 3.3/12.5 & 230 & 0.20 & Jul. 2005 \\
          \twCO{} & \Jone{} & 115.271202 & PdBI & C & $ 2.7 \times 2.5$ & 12 & 0.2 & 7.0/12.0 & 230 & 0.52 & Dec. 2005 \\
          \hline
        \end{tabular}
        }
    \smallskip
    $^{a}$ The noise values quoted here are the noises at the mosaic phase center
    (Mosaic noise is inhomogeneous due to primary beam correction; it 
    steeply increases at the mosaic edges).
\par
    \smallskip
    %\centerline
{
        \begin{tabular}{rcrlcccrclccr}
          \hline \hline\noalign{\smallskip}
          Molecule & Transition & Frequency  & Instrument & \# Pix. & $F_{\rm eff}$  & $B_{\rm eff}$  & Resol. & Resol. & Int. time$^{a}$ & $T_{\rm sys}$  & Noise$^{b}$ & Obs. date \\
                   &            & GHz        &            &         &         &         & arcsec & \kms{} & h           &    K    &  K          &   \\
          \hline\noalign{\smallskip}
          \twCO{} & \Jone{} & 115.271202 & 30~m/AB100 & 2 & 0.95 & 0.75 & 22.5 & 0.20 & 2.4/3.6  & 240 & 0.26 & Sep. 2005 \\
          \twCO{} & \Jtwo{} & 230.538000 & 30~m/AB230 & 2 & 0.91 & 0.52 & 22.5 & 0.20 & 2.4/3.6  & 320 & 0.16 & Sep. 2005 \\
          \hline
        \end{tabular}}
    \smallskip
    $^{a}$ Two values are given for the integration time: the on-source
    time and the telescope time.\\
    $^{b}$ Noise values estimated at the position of NRAO150.
    \label{tab:obs}
  \end{table}