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Initial parameters of compact stars

The stars with initial masses leave a WD in the end of evoluiton, with the WD masses and chemical composition depending on the binary system's parameters. Stars with collapses to form NS of 1.4 M; when a BH with a mass of is formed, where is either the mass of the pre-collapsing star (in the case of low stellar wind mass-loss scenario), or the initial mass of the star (in teh case of the high stellar wind mass-loss scenario). NS and WD are assumed to have a magnetic field randomly distributed within a range G and G correspondingly.

The evolution of a compact star is considered as the change of its spin period and hence the change of regime of interaction with the surrounding plasma supplied by the second component (for more detail see Lipunov 1992, Lipunov & Popov 1995).

The accretion rate is limited by the Eddington luminosity or by the surface nuclear burning of the accreted matter (for WD). In that case supercritical regimes with mass outflow may happen.

When an accreting WD reaches the Chandrasekhar limit, it assumes to explode as a SN type Ia with or without NS formation. Analogously, after reaching the Oppengeimer-Volkov limit, a NS collapses into a BH.

Sergei B. Popov
Fri Jun 21 19:17:07 MSD 1996