Nucleocosmochronology

Nucleocosmochronology or nuclear cosmochronology is a technique used to determine timescales for astrophysical objects and events. It compares the observed ratios of abundances of heavy radioactive and stable nuclides to the primordial ratios predicted by nucleosynthesis theory in order to calculate the age of formation of astronomical objects.[1]

Nucleocosmochronology has been employed to determine the age of the Sun (4.57±0.02 billion years) and of the Galactic thin disk (8.8±1.8 billion years),[2][3][4] among others. It has also been used to estimate the age of the Milky Way itself, as exemplified by a recent study of Cayrel's Star in the Galactic halo, which due to its low metallicity, is believed to have formed early in the history of the Galaxy.[5] Limiting factors in its precision are the quality of observations of faint stars and the uncertainty of the primordial abundances of r-process elements.

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ReferencesEdit

  1. ^ Bland-Hawthorn, Joss; Freeman, Kenneth (2014). "Near Field Cosmology: The Origin of the Galaxy and the Local Group". The Origin of the Galaxy and Local Group. Berlin, Heidelberg: Springer Berlin Heidelberg. pp. 1–144. Bibcode:2014SAAS...37....1B. doi:10.1007/978-3-642-41720-7_1. ISBN 978-3-642-41719-1. ISSN 1861-7980.
  2. ^ del Peloso et al., "The age of the Galactic thin disk from Th/Eu nucleocosmochronology I. Determination of Th/Eu abundance ratios." Astronomy & Astrophysics, 434, (2005) 275.
  3. ^ del Peloso et al., "The age of the Galactic thin disk from Th/Eu nucleocosmochronology II. Chronological analysis." Astronomy & Astrophysics, 434, (2005) 301.
  4. ^ del Peloso et al., "The age of the Galactic thin disk from Th/Eu nucleocosmochronology III. Extended sample." Astronomy & Astrophysics, 440, (2005) 1153.
  5. ^ Hill, V.; Plez, B.; Cayrel, R.; Beers, T. C.; Nordström, B.; Andersen, J.; Spite, M.; Spite, F.; Barbuy, B.; Bonifacio, P.; Depagne, E.; François, P.; Primas, F. (2002). "First stars. I. The extreme r-element rich, iron-poor halo giant CS 31082-001". Astronomy & Astrophysics. EDP Sciences. 387 (2): 560–579. arXiv:astro-ph/0203462. Bibcode:2002A&A...387..560H. doi:10.1051/0004-6361:20020434. ISSN 0004-6361.