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Nuclear field shift effect as a possible cause of Te isotopic anomalies in the early solar system—An alternative explanation of Fehr et al. (2006 and 2009)
Author(s) -
Moynier Frédéric,
Fujii Toshiyuki,
Albarède Francis
Publication year - 2009
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2009.tb01203.x
Subject(s) - isotope , normalization (sociology) , formation and evolution of the solar system , physics , mass independent fractionation , astrophysics , isotope fractionation , nuclear physics , solar system , sociology , anthropology
— We explore the possibility that Te isotopic anomalies measured in Ca‐Al‐rich inclusions (Fehr et al. 2009) and in leachates of carbonaceous chondrites (Fehr et al. 2006) may be due to mass‐independent effects controlled by nuclear field shift rather than to nucleosynthetic processes. Fehr et al.'s spectrum of mass‐independent anomalies of Te isotopes shows a smooth correlation with mass number and nuclear charge distribution. Ratios of even to odd isotopes, as the 125 Te/ 126 Te ratio used by these authors for normalization are particularly prone to nuclear field shift effects. We show that the alternative normalization of isotopic ratios to 130 Te/ 126 Te strongly reduces the trend of isotopic fractionation with mass number, leaving only 125 Te as truly anomalous. For both normalizations ( 125 Te/ 126 Te and 130 Te/ 126 Te), Fehr et al.'s results fit the theory of Bigeleisen (1996), which suggests that the nuclear field shift effect can potentially account for the observed Te isotope abundances, as an alternative to nucleosynthetic processes. We propose that these mass‐independent effects may be acquired during accretion of sulfides from the solar nebula.