Eects of input physics on the collapse condition of the oxygen-neon-magnesium core

The evolution of a 8 - 10 solar mass main-sequence star leaves an oxygen-neon-magnesium (ONeMg) core close to the Chandrasekhar mass with a central density about 10^9.95 g cm⁻³. The consequent electron capture of ¹⁶O and ²⁰Ne in the core triggers the oxygen-neon deflagration. It has been shown that the collapse criteria is sensitive to the choice of input physics, in particular the flame physics. In this article we study the oxygen deflagration by two-dimensional simulations of an ONeMg core using the turbulent deflagration model. We consider stellar models with different input physics, including the initial flame structure, central density and relativistic effects. We found that in general collapse occurs in most models with a central density above 10^9.90 g cm⁻³. Also, the initial ignited mass affects the collapse density strongly. On the other hand, the collapse condition does not vary strongly with the inclusion of relativistic effects. Our results suggest that the low mass neutron stars observed in binary pulsars are likely to be produced by the collapse of the ONeMg core left behind by AGB stars. Furthermore, an accurate modelling from stellar evolution is essential for an accurate prediction of the ONeMg core final fate.