A compact review of the main characteristics of asymptotic giant
branch stars (briefly: AGB) will be described. We describe a link with
observations and basic features of theoretical modeling of these important
evolutionary phases of these stars.
The AGB stars are the progenitors of white dwarfs in the galaxy,
and they produce about half of the heavy elements and their isotopes beyond
iron element via the s-process nucleosynthesis, which is a slow neutron-capture
process linked to α radioactive decay. The essential
neutron source is mainly due to the 13C(α,n)16O reaction, and to a lesser
extent the 22Ne(α,n)25Mg reaction. In addition, several important elements are
produced such as 19 F and 27 Al during the thermal pulsation of the stars. The summary in sect. 6 contains the
most important aspects of the AGBs. It is a challenging astrophysical problem
to describe the process of convective mixing coupled to nuclear reactions
during thermal pulsations including the effect of the magnetic field to obtain
the right amount of 13 C that can lead to s process abundances compatible with
observation. Important remaining problems are presented in the present work.
Author(s)
Details
Mounib
F. El Eid
Department of Physics, American University of Beirut, Lebanon and
Department of Physics & Astronomy, Clemson University, SC, USA.
Please see the book here:- https://doi.org/10.9734/bpi/crpps/v3/1158
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