\begin{table}%t1 \caption{\label{tab_26Alringmass}Galactic mass distribution of $^{26}$Al obtained from our analysis of 4 years of INTEGRAL/SPI observations (see text).} %\centering \par \begin{tabular}{lr} \hline\hline ring 1 (0--3~kpc) & 0.17 $\pm$ 0.07~$M_{\odot}$\\ \celltspace \cellbspace ring 2 (3--6~kpc) & 1.18 $\pm$ 0.15~$M_{\odot}$\\ \celltspace \cellbspace ring 3 (6--8~kpc) & 0.18 $\pm$ 0.08~$M_{\odot}$\\ \celltspace \cellbspace ring 4 (8--9~kpc) & 0.15 $\pm$ 0.04~$M_{\odot}$\\ \celltspace \cellbspace ring 5 (9--12~kpc) & --0.28 $\pm$ 0.18~$M_{\odot}$\\ \celltspace Total $^{26}$Al mass & 1.68 $\pm$ 0.19~$M_{\odot}$\\ \hline \end{tabular} \end{table}