\begin{table}%t6 \caption{\label{n4441chap_coprop}Integrated intensity line ratios derived from the CO measurements at the central position.} \small%\centerline { \begin{tabular}{lc} \hline\hline \noalign{\smallskip} Property& Result\\ \hline\noalign{\smallskip} $M_{\rm H2}$ ($10^8$ \msun) & 4.6\\ $^{12}$CO(2--1)/$^{12}$CO(1--0)& 0.5 (0.06)\\ $^{13}$CO(2--1)/$^{13}$CO(1--0) & 0.42 (0.17)\\ $^{12}$CO(1--0)/$^{13}$CO(1--0) & 21 (3.5)\\ $^{12}$CO(2--1)/$^{13}$CO(2--1) & 25 (7.6)\\ \hline \end{tabular}} \medskip In brackets, the errors in the line ratio are given, following standard error propagation calculations. A~source size of~22\arcsec\ is used to evaluate the line ratios. \end{table}