\begin{table}%T1
      \caption{\label{tab1}HD$^{18}$O  line parameters.}
\small%\centering
\par
\begin{tabular}{lllll}
\hline\hline\noalign{\smallskip}
\multicolumn{1}{c}{$\nu$(GHz)} & 
\multicolumn{1}{c}{Transition} & 
\multicolumn{1}{c}{$\int T_{\rm mb}{\rm d}v$} &
\multicolumn{1}{c}{$v$} & 
\multicolumn{1}{c}{$\Delta v$} \\
&& (K km s$^{-1}$) & (km s$^{-1}$) & (km s$^{-1}$) \\\hline
592.402 & $2_{11}{-}2_{02}$ & 1.7 (0.1) & 7.1 (0.1) & 6.4 (1.2) \\
746.476 & $3_{12}{-}3_{03}$ & 2.9 (0.2) & 6.7 (0.2) & 6.3 (0.3) \\
883.189 & $1_{11}{-}0_{00}$ & 2.1 (0.1) & 7.1 (0.1) & 4.9 (0.3) \\
994.347\tablefootmark{a} & $3_{03}-2_{12}$ & 3.2 (0.2) & 7.9 (0.2) & 4.7 (0.3) \\
\hline 
\end{tabular}
\tablefoot{Two other transitions ($2_{11}{-}1_{10}$, $2_{02}{-}1_{11}$) might be present, but are not listed due to significant line blending. 
\tablefoottext{a}{Blended with unidentified line; emission clearly isolated using Gaussian fits (e.g. Fig.~\ref{fig:hdo}).} 
}\vspace*{-4mm}
\end{table}