Instabilities in the ionization zones around the first stars

We consider the evolution of the ionization zone around Population III stars with M _* ?? 25?C200M _?? in protogalaxies with M ?? 10⁷ M _?? at redshifts z = 12, assuming that the dark-energy profile is a modified isothermal sphere. We study the conditions for the growth of instabilities in the ionization zones. The Rayleigh-Taylor and thermal instabilities develop efficiently in the ionization zones around 25?C40M _?? stars, while this efficiency is lower for stars withM _* ?? 120M _??. For more massive stars (??200M _??), the flux of ionizing photons is strong enough to considerably reduce the gas density in the ionization zone, and the typical lifetimes of stars (??2 Myr) are insufficient for the growth of instabilities. The gas in a protogalaxy with M ?? 10⁷ M _?? with a 200M _?? central star is completely ionized by the end of the star??s lifetime; in the case of a 120M _?? central star, only one-third of the total mass of gas is ionized. Thus, ionizing photons from stars with M _* ? 120M _?? cannot leave protogalaxies with M ? 10⁷ M _??. If the masses of the central stars are 25 and 40M _??, the gas in protogalaxies of this mass remains essentially neutral. We discuss the consequences of the evolution of the ionization zones for the propagation of the envelope after the supernova explosions of the strs and the efficiency of enrichment of the intergalactic medium in heavy elements.