| Autor: |
Kinoshita N; Research Facility Center for Science and Technology, University of Tsukuba, Tsukuba, Japan., Paul M, Kashiv Y, Collon P, Deibel CM, DiGiovine B, Greene JP, Henderson DJ, Jiang CL, Marley ST, Nakanishi T, Pardo RC, Rehm KE, Robertson D, Scott R, Schmitt C, Tang XD, Vondrasek R, Yokoyama A |
| Jazyk: |
angličtina |
| Zdroj: |
Science (New York, N.Y.) [Science] 2012 Mar 30; Vol. 335 (6076), pp. 1614-7. |
| DOI: |
10.1126/science.1215510 |
| Abstrakt: |
The extinct p-process nuclide (146)Sm serves as an astrophysical and geochemical chronometer through measurements of isotopic anomalies of its α-decay daughter (142)Nd. Based on analyses of (146)Sm/(147)Sm α-activity and atom ratios, we determined the half-life of (146)Sm to be 68 ± 7 (1σ) million years, which is shorter than the currently used value of 103 ± 5 million years. This half-life value implies a higher initial (146)Sm abundance in the early solar system, ((146)Sm/(144)Sm)(0) = 0.0094 ± 0.0005 (2σ), than previously estimated. Terrestrial, lunar, and martian planetary silicate mantle differentiation events dated with (146)Sm-(142)Nd converge to a shorter time span and in general to earlier times, due to the combined effect of the new (146)Sm half-life and ((146)Sm/(144)Sm)(0) values. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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