\begin{table}%t2
\caption{Line data of \object{IRAS2} discussed in this
Paper.\label{obs_overview}}
%\centerline
{\begin{tabular}{llll}\hline\hline
Molecule & Line & Rest freq.   & Observed with    \\ \hline
CH$_3$OH   & $2_1{-}1_1$         & \phantom{1}97.5828 & OVRO \\[0.5ex]
CS         & $2{-}1$             & \phantom{1}97.9810 & OSO, OVRO \\
           & $3{-}2$             & 146.9690           & IRAM 30m \\
           & $5{-}4$             & 244.9356           & IRAM 30m, JCMT$^{b}$ \\
           & $7{-}6$             & 342.8830           & JCMT$^{b}$ \\[0.5ex]
C$^{34}$S  & $2{-}1$             & \phantom{1}96.4129 & IRAM 30m, BIMA \\
           & $5{-}4$             & 241.0161           & JCMT \\[0.5ex]
HCN        & $1{-}0$$^{a}$       & \phantom{1}88.6318 & OSO, BIMA \\[0.5ex]
H$^{13}$CO$^+$    & $1{-}0$             & \phantom{1}86.7543 & OSO, OVRO \\[0.5ex]
HCO$^+$    & $1{-}0$             & \phantom{1}89.1885 & OSO, BIMA \\[0.5ex]
N$_2$H$^+$ & $1{-}0$$^{a}$       & \phantom{1}93.1737 & OSO, BIMA \\[0.5ex]
SiO        & $2{-}1$             & \phantom{1}86.8470 & OVRO \\[0.5ex]
SO         & $2_2{-}1_1$         & \phantom{1}86.0940 & OVRO \\[0.5ex]
SO$_2$     & $7_{3,5}{-}8_{2,6}$ & \phantom{1}97.7023 & OVRO \\\hline
\end{tabular}}
\par
\smallskip
$^{a}$Hyperfine splitting observed in one
setting. \\
$^{b}$Archival data.
\end{table}