Observations of neutron-capture elements in the early galaxy

• Published in: Nuclear physics. A Vol. 718; pp. 29 - 36
• Main Authors: Sneden, C., Cowan, J.J., Lawler, J.E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 28.07.2003
• ISSN: 0375-9474
• DOI: 10.1016/S0375-9474(03)00676-6

Neutron-capture elements in low metallicity Galactic halo stars vary widely both in overall contents and detailed abundance patterns. This review discusses recent observational results of the n-capture elements, discussing the implications for early Galactic nucleosynthesis of: (a) the star-to-star “bulk” variations in the n-capture/Fe abundance ratios; (b) the distinct signature of rapid n-capture synthesis events in many (most?) of the lowest metallicity stars; (c) the existence of metal-poor stars heavily enriched in the products of slow n-capture synthesis reactions; and (d) the now-routine detection of radioactive thorium (and even uranium in one and possibly two cases) in the spectra of metal-poor stars.