Chemical evolution of Mg isotopes versus the time variation of the fine structure constant.
We show that the synthesis of (25,26)Mg at the base of the convective envelope in low-metallicity asymptotic giant branch stars can produce the isotopic ratios needed to explain the low-z subset (with z<1.8) of the many-multiplet data from quasar absorption systems without invoking a time variation of the fine structure constant. This is supported by observations of high abundances of the neutron-rich Mg isotopes in metal-poor globular-cluster stars. We conclude that the quasar absorption spectra may be providing interesting information on the nucleosynthetic history of such systems.
Department of Physics, Center for Astrophysics, University of Notre Dame, Notre Dame, IN 46556, USA.
T
T
Ashenfelter
Grant J
GJ
Mathews
Keith A
KA
Olive