\begin{table}%t12
\caption{\label{t:prcnmodel}Parameters of our best-fit LTE~model of \textit{n}-propyl cyanide with two velocity components.}
\small%\centerline
 {
\begin{tabular}{ccccc}
 \hline\hline
%&&&& \\[-8pt]
 \multicolumn{1}{c}{Size$^{a}$} & \multicolumn{1}{c}{$T_{{\rm rot}}$$^{b}$} & \multicolumn{1}{c}{$N^{c}$} & \multicolumn{1}{c}{$\Delta V^{d}$} & \multicolumn{1}{c}{$V_{{\rm off}}$$^{e}$} \\ 
 \multicolumn{1}{c}{\scriptsize ($''$)} & \multicolumn{1}{c}{\scriptsize (K)} & \multicolumn{1}{c}{\scriptsize (cm$^{-2}$)} & \multicolumn{1}{c}{\scriptsize (km~s$^{-1}$)} & \multicolumn{1}{c}{\scriptsize (km~s$^{-1}$)} \\ 
 \multicolumn{1}{c}{(1)} & \multicolumn{1}{c}{(2)} & \multicolumn{1}{c}{(3)} & \multicolumn{1}{c}{(4)} & \multicolumn{1}{c}{(5)} \\ 
 \hline
%&&&& \\[-8pt]
 3.0 &  150 & $ 1.50 \times 10^{16}$ & 7.0 & --1.0 \\  3.0 &  150 & $ 6.60 \times 10^{15}$ & 7.0 & 9.0 \\  
 \hline
 \end{tabular}}
\medskip 
 Notes:
 $^a$~Source diameter (\textit{FWHM}).
 $^b$~Temperature.
 $^c$~Column density.
 $^d$~Linewidth (\textit{FWHM}).
 $^e$~Velocity offset with respect to the systemic velocity of Sgr~B2(N) $V_{{\rm lsr}} = 64$~km~s$^{-1}$.
\end{table}