\begin{table}%t1
%\centering
\par
\caption{\label{tab1}Observational data.}
\begin{tabular}{l c c c c l}
\hline\hline\noalign{\smallskip}
Line & Survey  & Beam & Velocity & Sensitivity & Ref.\\
& facility & & chan. & chan.&  \\
& & & [km s$^{-1}$] & [K km s$^{-1}$] & \\
\hline
[CII] & GOT C+ & 12\arcsecs  & 1.0 & 0.1--0.2 & 1,2 \\
 1.9~THz & {\it Herschel} HIFI & & & & \\
\hline\noalign{\smallskip}
HI & SGPS/ATCA &  132\arcsecs  & 0.84 & 1.6 & 3\\
 &VGPS/VLA& 60\arcsecs  & 0.84 & 2.0 & 4\\
\hline\noalign{\smallskip}
$^{12}$CO (1-0) & ATNF & 33\arcsecs  & 0.8 & 0.6 & 5\\
$^{13}$CO (1-0) & Mopra &   & 0.8 & 0.1 & \\
C$^{18}$O (1-0) &22-m  &   & 1.6 & 0.1 & \\
\hline
\end{tabular}
\vspace*{-2mm}
\tablefoot{\tablefoottext{1}{This paper;} 
\tablefoottext{2}{\citet{LangerESLAB2010};} 
\tablefoottext{3}{McClure-Griffiths et~al. (2005);} 
\tablefoottext{4}{\citet{Stil2006};}
\tablefoottext{5}{\citet{Pineda2010}.}}
%\vspace*{-1.5mm}
\end{table}