\begin{table}%t1
\caption{\label{t1}Summary of observational results.}
%\centering
\par
\begin{tabular}{lccc}
\hline\hline\noalign{\smallskip}
 %& & &  \\
Source & Line &  Peak $T_{\rm mb}$ or 3$\sigma$ limit  & 1$\sigma$ 
 noise ~~(res.) \\
       &      &              mK                   & mK   \\
\hline
 & & & \\[-2.5mm] 
R Aqr    & $^{12}$CO 2--1 & 30            & 2 ~~(2.6 \kms) \\
         & $^{12}$CO 1--0 & $\sim$6      & 2 ~~(5.2 \kms) \\
         & $^{13}$CO 2--1 & $<$18 & 6 ~~(2.7 \kms) \\
         & $^{13}$CO 1--0 & $<$18 & 6 ~~(2.6 \kms) \\
         & SiO 5--4       & $<$19 & 6 ~~(2.8 \kms) \\
\hline
 & & & \\[-2.5mm]
CH Cyg   & $^{12}$CO 2--1 & 9      & 2 ~~(2.6 \kms) \\
         & $^{12}$CO 1--0 & $\sim$4.5      & 1.4 ~~(5.4 \kms) \\
\hline
 & & & \\[-2.5mm]
HM Sge   & $^{12}$CO 2--1 & $<$19 & 6.5 ~~(2.6 \kms) \\
         & $^{12}$CO 1--0 & $<$26 & 9 ~~(2.6 \kms) \\
\hline
\end{tabular}
\tablefoot{Peak main-beam temperature or 3$\sigma$ limit,
  1$\sigma$ noise, and spectral resolution with which the noise was
  calculated.}\vspace*{4mm}
\end{table}