[SN, SNR, and Isolated NS -- Oral ]

Progenitors of Type Ia Supernovae in early type galaxies.

Marat Gilfanov, Max-Planck-Institute for Astrophysics
Marat Gilfanov \& Akos Bogdan (MPA, Garching)

Although there is a nearly universal agreement that SNeIa areassociated with the thermonuclear disruption of a CO white dwarfreaching the Chandrasekhar mass limit, the exact nature of theirprogenitors is still unknown. The single degenerate scenario envisagesa white dwarf accreting matter from a non-degenerate companion in abinary system. Gravitational and nuclear energy of the accretedmatter is released in the form of electromagnetic radiation and/orkinetic power of Classical Novae explosions {\em prior} to theSupernova event. We show that combined X-ray output of SNIaprogenitors and statistics of Classical Novae predicted in the singledegenerate scenario are inconsistent with X-ray and opticalobservations of nearby early type galaxies. No more than $\sim5-10$per cent of SNeIa associated with old stellar population can beproduced via single degenerate evolutionary channel, unless ourunderstanding of accretion and nuclear fusion on the white dwarfsurface is fundamentally flawed.