\begin{table}%t4
\caption{\label{online1}Summary of o-H$_2$$^{18}$O~$1_{10}$ -- 1$_{01}$ model results.  }
\scriptsize
%\centering
\par
\begin{tabular}{cccc}
\hline \hline\noalign{\smallskip}
\multicolumn{2}{c} {Envelope abundance} & $T_{\rm MB}^{\rm peak}$ & $\int T_{\rm MB}~{\rm d}\varv$ \\
Inner & Outer & (K) & (K km s$^{-1}$) \\
\hline\noalign{\smallskip}
$1 \times 10^{-5}$ &     $3 \times 10^{-10}$ &   0.017  &  0.071  \\
$3 \times 10^{-6}$ &     $3 \times 10^{-10}$ &   0.018  &  0.075  \\
$1 \times 10^{-6}$ &     $3 \times 10^{-10}$ &   0.017  &  0.069  \\
$3 \times 10^{-7}$ &     $3 \times 10^{-10}$ &   0.016  &  0.065  \\
$1 \times 10^{-7}$ &     $3 \times 10^{-10}$ &   0.015  &  0.060  \\
$3 \times 10^{-8}$ &     $3 \times 10^{-10}$ &   0.014  &  0.054  \\
$1 \times 10^{-8}$ &     $3 \times 10^{-10}$ &   0.014  &  0.050  \\
 \noalign{\smallskip}
$1 \times 10^{-5}$ &     $2 \times 10^{-10}$ &   0.015  &  0.063  \\
$3 \times 10^{-6}$ &     $2 \times 10^{-10}$ &   0.014  &  0.060  \\
$1 \times 10^{-6}$ &     $2 \times 10^{-10}$ &   0.014  &  0.060  \\
$3 \times 10^{-7}$ &     $2 \times 10^{-10}$ &  0.013  &  0.052  \\
   \noalign{\smallskip}
$1 \times 10^{-5}$ &     $1 \times 10^{-10}$ &   0.010  &  0.043  \\
$1 \times 10^{-6}$ &     $1 \times 10^{-10}$ &  0.009  &  0.038  \\
$3 \times 10^{-7}$ &     $1 \times 10^{-10}$ &   0.009  &  0.036  \\
$1 \times 10^{-7}$ &     $1 \times 10^{-10}$ &   0.008  &  0.032  \\
$3 \times 10^{-8}$ &     $1 \times 10^{-10}$ &   0.007  &  0.027  \\
\hline
\end{tabular} 
\tablefoot{The observed line has a $T_{\rm MB}^{\rm peak} =  0.015$~K and an $\int T_{\rm MB}~{\rm d}\varv =  0.071$~K~km$^{-1}$, the best fitting model is selected by comparison with the latter.}
\end{table}