\begin{table}%t4 \caption{\label{param_IKTau}Parameters of the models with best goodness-of-fit for \object{IK~Tau}.} %\centering \par \begin{tabular}{lcccc} \hline \hline \noalign{\smallskip} & Model 1 & Model 2 & Model 3 & 95\% confidence\\ based on & \multicolumn{1}{c}{CO} & \multicolumn{1}{c}{CO \& HCN} & \multicolumn{1}{c}{CO \& HCN} & interval for\\ $v(r)$ & momentum eq. & momentum eq. & power-law $\beta~=~1$ & model 3\\ parameter & value & value & value & \\ \hline \Teff [K] & 2200 & 2200 & 2200 & 100 \\ $R_{\star}$ [$10^{13}$~cm] & 2.5 & 1.5 & 1.5 & 1.0 \\ $[$CO/H$_2]$ [$10^{-4}$] & \emph{2} & \emph{2} & \emph{2}& $-$ \\ distance [pc] & 250 & 265 & 265 & 20 \\ $R_{\rm{inner}}$ [\Rstar] & 2.2 & 8.7 & 8.7 & 2 \\ $R_{\rm{outer}}$ [\Rstar] & 15~170 & 27~000 & 27~000 & $-$ \\ $v_{\infty}$ [km~s$^{-1}$] & \emph{17.7} & \emph{17.7}& \emph{17.7} & $-$ \\ \Mdot$(r)$ [{\Msun}/yr] & $8 \times 10^{-6}$ & $9 \times 10^{-6}$& $8 \times 10^{-6}$& $1 \times 10^{-6}$\\ $^{12}$C/$^{13}$C & 20 & 16 & 14 & 2 \\ \hline \end{tabular} \tablefoot {Details for each model are given in the text. The numbers in italics are input parameters that have been kept fixed at the given value.} \vspace*{5mm} \end{table}