26Al production in the Vela and Orion regions

The allsky image of Al-26 radiation at 1.809 MeV with COMPTEL suggests that clusters of massive stars dominate the Galactic production of Al-26. Studies of rather well-known localized regions are most promising to further this interpretation. In the Vela region, excessive emissivity is found compared to other Galactic regions. This may be due to few prominent foreground sources, such as the Vela SNR and RX J0852.0-4622 combined; but more plausibly the star forming activity along the Vela Molecular Ridge is enhanced in general, too. In the anticenter region, the detected Al-26 emission appears related to nucleosynthetic activity in the Orion OBI association: It seems plausible that ejecta are being vented into the Eridanus bubble blown by earlier massive stars' activity. (C) 2002 Elsevier Science B.V. All rights reserved.