\begin{table}%t1
    \caption{\label{tab:pdb}Observation parameters.}
    %\begin{center}

      \begin{tabular}{lrrc}
        \hline\hline
        & \multicolumn{2}{c}{Phase center} & Number of fields \\
        Mosaic 1 &  $\rm \alpha_{2000} = 05^h40^m54.27^s $ & $ \delta_{2000} =
        -02^\circ 28' 00''$ & 7 \\
        Mosaic 2 &  $\rm \alpha_{2000} = 05^h40^m53.00^s $ & $ \delta_{2000} =
        -02^\circ 28' 00'' $ & 4 \\
        \hline
      \end{tabular}
      \smallskip{}
      \begin{tabular}{lrcccr}
        \hline
        Molecule and Line & Frequency  &   Beam & PA     & Noise$^{a}$ & \multicolumn{1}{c}{Obs. date} \\
        & GHz        & arcsec & $\deg$ & \Kkms{}     &     \\
        \hline
        Mosaic 1 \\
        \cCCCHH{} $2_{1,2}{-}1_{0,1}$     &  85.339 & $6.13 \times 4.75$ & 36 & 3.1$\times 10^{-2}$ & Mar. 2002 and Apr. 2002 \\
        \CCCCH{}-1 $N=9{-}8,\ J=19/2{-}17/2$    &  85.634 & $6.11 \times 4.74$ & 36 & $2.6\times 10^{-2}$ & Mar. 2002 and Apr. 2002 \\
        \CCCCH{}-2 $N=9{-}8,\ J=17/2{-}15/2$    &  85.672 & $6.11 \times 4.74$ & 36 & $3.4\times 10^{-2}$ & Mar. 2002 and Apr. 2002 \\
        \CCH{}-1 $N=1{-}0,\  J=3/2{-}1/2\ F=2{-}1$ &  87.316 & $7.24 \times 4.99$ & 54 & $3.4\times 10^{-2}$ & Dec. 2002 and Mar. 2003 \\
        \CCH{}-2 $N=1{-}0,\ J=3/2{-}1/2\ F=1{-}0$ &  87.328 & $7.24 \times 4.99$ & 54 & $2.5\times 10^{-2}$ & Dec. 2002 and Mar. 2003 \\
        \CCH{}-3 $N=1{-}0,\ J=1/2{-}1/2\ F=1{-}1$ &  87.402 & $7.24 \times 4.99$ & 54 & $3.4\times 10^{-2}$ & Dec. 2002 and Mar. 2003 \\
        \CCH{}-4 $N=1{-}0,\ J=1/2{-}1/2\ F=0{-}1$ &  87.407 & $7.24 \times 4.99$ & 54 & $2.3\times 10^{-2}$ & Dec. 2002 and Mar. 2003 \\
        \CeiO{} \Jtwo{}                 & 219.560 & $6.54 \times 4.31$ & 65 & $9.8\times 10^{-2}$ &              Mar. 2003 \\
        \hline
        Mosaic 2 \\
        \twCO{} \Jone{} & 115.271 & $5.95 \times 5.00$ & 65 & $1.2\times 10^{-1}$ & Nov. 1999 \\
        \twCO{} \Jtwo{} & 230.538 & $2.97 \times 2.47$ & 66 & $1.7\times 10^{-1}$ & Nov. 1999 \\
        \hline
      \end{tabular}
      %\end{center}

    $^{a}$ The noise values quoted here are the noises at the mosaic center
    (Mosaic noise is inhomogeneous due to primary beam correction; it 
    steeply increases at the mosaic edges). Those noise values have been 
    computed in 1\kms{} velocity bin.
      \end{table}