The synthesis of²⁶Al during combined hydrogen and helium-burning reactions

Abstract

We have studied the synthesis of²⁶Al during combined hydrogen and helium-burning processes in high temperature and density conditions. The possible sites for these processes are believed to be the neutron star surfaces where the density ranges from ρ=10⁴−10⁷ g cm⁻³ and temperature range from 10⁸−8×10⁸ K. The screening effect which leads to an enhancement of nuclear reaction rates is taken into account whenever necessary. A detailed calculation of the abundances of²⁶Al and²⁷Al isotopes is presented here. Finite amounts of²⁶Al is found to be produced atT=2×10⁸ K and ρ=10⁸ g cm⁻³ due to these combined reactions. This situation is likely to be realized during the γ-ray burst events on neutron star surface. The amount of material processed in the burst sources is very little compared to the amount of material processed in Novae or Supernovae. Thus it is suggested that rather than contributing to the overall amount of²⁶Al, γ-ray bursts are likely to contribute more significantly to the inhomogeneity of²⁶Al distribution in interstellar medium.