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SYNTHESIS OF THE S-ONLY 122,123,124 TE ISOTOPES AND THE SELECTIVE DEPLETION OF 123 TE BY ELECTRON CAPTURE PROCESS IN MASSIVE STARS

2016; IOP Publishing; Volume: 819; Issue: 2 Linguagem: Inglês

10.3847/0004-637x/819/2/118

1538-4357

K. Takahashi, K. Blaum, Yu. N. Novikov,

Stellar, planetary, and galactic studies

ABSTRACT We investigate the production ratios of the naturally occurring s-only nuclides <?CDATA ${}^{122-124}$?> <?MML 122 − 124 ?> Te by solving a nuclear network in the mass number <?CDATA $120\leqslant A\leqslant 124$?> <?MML 120 ≤ A ≤ 124 ?> region under some conditions representing those in the helium–hydrogen inter-shell in low-mass AGB stars as well as those in the helium burning and the carbon burning phases in massive stars. We show that the electron-capture process on 123 Te (the natural half-life <?CDATA $\gt {10}^{16}$?> <?MML > 10 16 ?> years) could proceed decisively fast during the late evolutionary phases of massive stars. We thus re-iterate and re-enforce the decades-old notion that detailed analysis of the relative <?CDATA ${}^{122-124}$?> <?MML 122 − 124 ?> Te abundances in due consideration of the selective 123 Te depletion in massive stars would set a stringent constraint on the s-process modelings. We stress that the relative abundance ratios of <?CDATA ${}^{122-124}$?> <?MML 122 − 124 ?> Te in the solar system become quite difficult to decipher if the s-process in massive stars contributes significantly to the synthesis of nuclides in this intermediate A region.