Excitation and destruction of nuclei in hot astrophysical plasma around black holes

Abstract

The importance of nuclear reactions in low-density astrophysical plasmas with ion temperaturesT >10^10 K has been recognized for thirty years. However, the lack of comprehensive data banks of relevant nuclear reactions and the limited computational power have not previously allowed detailed theoretical studies. Recent developments in these areas make it timely to conduct comprehensive studies of the nuclear properties of very hot plasmas formed around compact relativistic objects such as black holes and neutron stars. Such studies are of great interest in the context of scientific programs of future low-energy cosmic gamma-ray spectrometry. In this work, using the publicly available code TALYS, we have built a large nuclear network relevant for temperatures exceeding 10^10 K. We then study the evolution of hot accretion plasmas for such high temperatures due to the destruction of nuclei at inelastic collisions, calculate the resulting gamma-ray spectra due to the superposition of prompt excitation gamma-ray lines, and present the results on the abundances of D, T, 3He.