\begin{table}%t4 \caption{\label{table:molecules}Table of the contributions to the oxygen column-density.} %%\centering \par \par \begin{tabular}{lllll} \hline\hline\noalign{\smallskip} Phase & Constituent & $N_{\rm O}~(10^{22}$ m$^{-2})$ & \% of $N_{\rm O}^{p}$\tablefootmark{a}& \% of $N_{\rm O}$\tablefootmark{b}\\ \hline \multirow{3}{*}{Gas} & \ion{O}{i} & $2.7 \pm 0.1 $ & $94 \pm 4 $ & \\ & \ion{O}{ii}, \ion{O}{iii}, \ion{O}{iv} & $0.10 \pm 0.05$ & $4 \pm 2 $ & $90 \pm 6 $\\ & \ion{O}{vii}, \ion{O}{viii} & $0.05 \pm 0.01$ & $2.0 \pm 0.5 $ & \\ \hline \multirow{2}{*}{Dust} & Silicates & $0.25 \pm 0.05$ & 85--100 & \multirow{2}{*}{$10\pm 2$} \\ & Aluminates & $<$0.04 & 0--15 & \\ \hline \multirow{2}{*}{Molecules} & H$_2$O ice & $<$0.07 & $\sim$65 & \multirow{2}{*}{0--2} \\ & CO & $<$0.04 & $\sim$35 & \\ \hline \end{tabular} \tablefoot{\tablefoottext{a}{\% of $N_{\rm O}^{p}$ represents the contribution of each constituent to the respective phase.} \tablefoottext{b}{\% of $N_{\rm O}$ give the contribution of the different phases to the total oxygen column density. See also Sect.~\ref{sec:dust_analysis} and Fig.~\ref{fig:oxygen_transmission} for the transmission of the main compounds.}} \vspace*{-3mm}\end{table}