Classical nova outbursts which occur on oxygen-neon-magnesium (ONeMg) white dwarfs have been suggested as possible candidates for the production of the (26) Al needed to account for the observed Galactic 1.809 MeV gamma -ray emission. Simplified estimates of the total amount of (26) Al produced by ONeMg novae in the Galaxy range from ~ 0.4M_sun to the full ~ 3 M_sun needed to explain the entire emission, assuming it is spatially homogeneous. Recent observations by the COMPTEL telescope aboard the Compton Gamma Ray Observatory revealed unexpected inhomogeneities and asymmetries in the spatial distribution of the emission, suggesting that a significant fraction of the emission originates from localized regions and thereby possibly reducing the required amount of (26) Al in a homogeneous background from ~ 3 M_sun to ~ 1 M_sun. These improved observations of the 1.809 MeV gamma -ray emission call for a more careful evaluation of the contribution of ONeMg novae to the production of (26) Al in the Galaxy. We combine results of a series of hydrodynamic studies of thermonuclear runaways on ONeMg white dwarfs using an extended nuclear network and a detailed population model of cataclysmic variables in order to explore in greater detail the range of the theoretically predicted amount of (26) Al produced by this population.
American Astronomical Society Meeting Abstracts
- Pub Date:
- December 1994