Oscillating structure of γ-bursts and their possible origin

Abstract

As it is well-known that the hydrodinamic collapse of the massive star iron core should lead to the production of a hot neutron star. The assumption is made that the thermonuclear burning of the envelope matter, accreting onto the hot neutron star, can proceed in the oscillatoric regime (analogously to that happens during heat explosion of the carbon-oxigene cores of stars with smaller masses). Local density oscillations in the vicinity of the neutron star surface can generate shock waves, in which the stratification of the electron-positron plasma from the rest of the matter can happen due to the light preasure. In the case of the spherically symmetric collapse of the compact star it can lead to the production of the expanding relativistic fireball shells with characteristic oscillation time of ~ 10^{-2} s, observed in the cosmological γ-bursts (GRB), can occur. It is pointed out that nonrotating massive Wolf-Rayet's (WR) stars could be the source for the GRB, whose collapses, according to a number of observations, can happen without any noticeable ejection of the envelope.