\begin{table}%t1 %\centering \par \caption{\label{tab-seds}{Results of fits of one and two emission components to the measured spectral energy distributions~(SEDs) of the MIPS, PACS, SPIRE data of M~33 shown in Fig.~\ref{fig-seds}.}} \begin{tabular}{rrrrrrr} \hline \hline \noalign{\smallskip} & Total & (1) & (2) & (3) & (4) \\ \hline \multicolumn{4}{l}{Isothermal fits} \\ $T$/[K] & 29 & 25 & 28 & 105 & 37 \\ $\beta$ & 0.5 & 1.4 & 0.8 & $-$1.8 & $-$0.8 \\ $\chi^2_{\rm red}$ & 45 & 44 & 45 & 3 & 6 \\ \noalign{\smallskip} \hline \multicolumn{4}{l}{Two-component fits with $\beta=2$} \\ $T_{\rm c}$/[K] & 16 & 20 & 17 & 14 & 12 \\ $T_{\rm w}$/[K] & 50 & 55 & 51 & 49 & 48 \\ $M_{\rm c}$/[$10^6~$\msol] & 8.0 & 1.0 & 2.4 & 3.6 & 4.0 \\ $M_{\rm c}/M_{\rm w}$ & 1000 & 900 & 900 & 1700 & 5600 \\ $\chi^2_{\rm red}$ & 0.41 & 0.23 & 0.33 & 0.42 & 1.8 \\ $M_{\rm gas}/M_{\rm c}$ & 250 & 230 & 180 & 160 & 200 \\ \hline \multicolumn{4}{l}{Two-component fits with $\beta=1.5$} \\ $T_{\rm c}$/[K] & 19 & 24 & 20 & 16 & 13 \\ $T_{\rm w}$/[K] & 55 & 77 & 57 & 52 & 51 \\ $M_{\rm c}$/[$10^{6}$~\msol] & 10 & 1.2 & 3.0 & 4.6 & 4.9 \\ $M_{\rm c}/M_{\rm w}$ & 500 & 3800 & 480 & 730 & 2200 \\ $\chi^2_{\rm red}$ & 0.14 & 0.10 & 0.12 & 0.20 & 1.8 \\ $M_{\rm gas}/M_{\rm c}$ & 200 & 190 & 150 & 120 & 160 \\ \hline \multicolumn{4}{l}{Two-component fits with $\beta=1$} \\ $T_{\rm c}$/[K] & 23 & 28 & 24 & 19 & 15 \\ $T_{\rm w}$/[K] & 62 & -- & 67 & 57 & 55 \\ $M_{\rm c}$/[$10^6~$\msol] & 12 & 1.6 & 3.6 & 5.7 & 5.8 \\ $M_{\rm c}/M_{\rm w}$ & 300 & -- & 440 & 330 & 870 \\ $\chi^2_{\rm red}$ & 0.22 & 0.6 & 0.26 & 0.30 & 2.4 \\ $M_{\rm gas}/M_{\rm c}$ & 170 & 140 & 120 & 100 & 140 \\ \hline \multicolumn{4}{l}{Total gas mass} \\ $M_{\rm gas}/[10^6~$\msol] & 2020 & 230 & 440 & 560 & 790 \\ \hline \end{tabular} \tablefoot{For the two-component fits, the dust emissivity index was kept fixed. $T_{\rm c}$, $T_{\rm w}$ are the temperatures of the cold and warm component. $M_{\rm c}$ is the total cold dust mass per annulus. $M_{\rm c}/M_{\rm w}$ is the dust mass ratio of both components. $\chi^2_{\rm red}$ is the $\chi^2$ divided by the number of observed parameters minus the number of fitted parameters minus 1. The 100~$\mu$m flux density measured in the outermost zone was not used for the fits. The columns give the radial annuli: Total: $0