\begin{table}%t1
\caption{\label{tab:lines}Observed HC$_3$N Lines Properties.}  
    %\centering
\par
\begin{tabular}{r c c c c c c c c c c}    
\hline\hline \noalign{\smallskip}    
Transition & Rest frequency & Tuning frequency & HPBW\tablefootmark{a} & $\int{T_{\rm A}^\star {\rm d}v}$ & $T_{\rm b}$\tablefootmark{b} & $\Delta V$\tablefootmark{c} & $\eta_{mb}$\tablefootmark{d} & $A_{u\ell}$\tablefootmark{e} & $E_u$\tablefootmark{f} & Ref.\tablefootmark{g} \\
$J_u-J_l$ $(v_6,v_7)$ & [GHz] & [GHz] & [$''$] & [mK km~s$^{-1}$] & [K] & [km~s$^{-1}$] & & [s$^{-1}$] & [K] & \\  
\hline     
& & & & & & & & &\\               
10--9 (0, 0) & 90.979 & 91.114 & 27 & 711 $\pm$ 20 & 1.5 & 134 & 0.77 & 5.8e-05 & 24.1 & IRAM 07-08 \\
     (1e, 0) & 91.128 & '' & 27	& $<$70 & -- & -- & 0.77 & 5.8e-05 & 736.6	& IRAM 07-08 \\
     (0, 1e) & 91.202 & '' & 27 & 159 $\pm$  17 & 0.4  & 108  & 0.77 & 5.8e-05 & 342.6	& IRAM 07-08 \\
     (0, 1f) & 91.333 & '' & 27 & 155  $\pm$ 14 & 0.4  & 110 & 0.77 & 5.8e-05 & 342.6 & IRAM 07-08 \\
16--15 (0, 0) & 145.561 & 145.561 & 17 & 1700 $\pm$ 80 & 1.7  &	130 & 0.70 & 2.4e-04 & 59.4 & Aalto 2007 \\
17--16 (0, 0) & 154.657 & 154.948 & 16 & 469 $\pm$ 52 & 0.5  & 117 & 0.67 & 2.9e-04 & 67.3 & IRAM 07-08 \\
      (1e, 0) & 155.032 &''  & 16 & $<$150 & --  & -- & 0.67 & 2.9e-04 & 779.2 & IRAM 07-08 \\
      (0, 1e) & 155.037 &''  & 16 & 316 $\pm$  59 & 0.3  & 141 & 0.67 & 2.9e-04 & 385.2 & IRAM 07-08 \\
      (0, 1f) & 155.259 &''  & 16 & 316 $\pm$  59 & 0.3  & 141 & 0.67 & 2.9e-04 & 385.3 & IRAM 07-08 \\
      (1e, 0) & 154.911 &''  & 16 & $<$150 & --  & -- & 0.67 & 2.9e-04 & 779.2 & IRAM 07-08 \\
25--24 (0, 0) & 227.418 & 227.757 & 11 & 2020 $\pm$  140 & 1.1  & 140 & 0.54 & 9.3e-04 & 143.0 & IRAM 12-07 \\		
      (1e, 0) & 227.793 & '' & 11 & 480 $\pm$ 110 & 0.3  & 125 & 0.54 & 9.3e-04 & 853.9 & IRAM 12-07 \\	
      (0, 1e) & 227.977 & '' & 11 & 928  $\pm$ 120 & 0.6 & 125 & 0.54 & 9.3e-04 & 459.9 & IRAM 12-07 \\
28--27 (0, 0) & 254.699 & 254.699 & 10 & 1720 $\pm$  100 & 0.9  & 141 & 0.47	& 1.3e-03 & 178.6 & IRAM 12-07 \\
28--27 (0, 0) & 254.699 & 255.018 & 10 & 1315 $\pm$  100 & 0.7 & 159 & 0.47 & 1.3e-03 & 178.6 & IRAM 07-08 \\
	 (1e, 0) & 255.119 &''  & 9.7 & $<$200 & --  & -- & 0.47 & 1.3e-03 & 889.1 & IRAM 07-08 \\
      (0, 1e) & 255.324 & '' & 9.7 & 327 $\pm$ 82 & 0.3  & 83 & 0.47 & 1.3e-03 & 495.2 & IRAM 07-08 \\
30--29 (0, 0) & 272.884 & 272.884 & 9	& 1300 $\pm$  200 & 0.5  & 182	& 0.44 & 1.6e-03 & 204.6 & IRAM 07-08 \\
38--37 (0, 0) & 345.609 & 345.609 & 14 & 1930 $\pm$  250$^{{\rm h}}$ & 1.8  & 120 & 0.63 & 3.3e-03 & 326.0 & JCMT 2007 \\ 	
\hline
\end{tabular}
\tablefoot{\tablefoottext{a}{Half power beam width.}
 \tablefoottext{b}{Brightness temperature, assuming a 2$''$ source size.}
 \tablefoottext{c}{Full width at half maximum from Gaussian fit.}
 \tablefoottext{d}{Main beam efficiency.}
 \tablefoottext{e}{Einstein's transition coefficient.}
 \tablefoottext{f}{Energy above ground of the upper level.}
 \tablefoottext{g}{Telescope and epoch.}
 \tablefoottext{h}{From Gaussian fit to the CO 3--2 spectrum, see Fig. \ref{fig:spec}.}}\vspace*{2mm}
\end{table}