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Evidence of Multiple r-Process Sites in the Early Galaxy: New Observations of CS 22892-052

Christopher Sneden·John J. Cowan·Inese I. Ivans·George M. Fuller·Scott Burles·Timothy C. Beers·James E. Lawler
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Abstract

First results are reported of a new abundance study of neutron-capture elements in the ultra-metal-poor (UMP; [Fe/H] = -3.1) halo field giant star CS 22892-052. Using new high resolution, high signal-to-noise spectra, abundances of more than 30 neutron-capture elements (Z>30) have been determined. Six elements in the 40 =56) stable neutron-capture elements in CS 22892-052 match well the scaled solar system r-process abundance distribution. From the observed Th abundance, an average age of ~= 16 +/- 4 Gyr is derived for cs22892-052, consistent with the lower age limit of ~= 11 Gyr derived from the upper limit on the U abundance. The concordance of scaled solar r-process and CS 22892-052 abundances breaks down for the lighter neutron-capture elements, supporting previous suggestions that different r-process production sites are responsible for lighter and heavier neutron-capture elements.

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Christopher Sneden, John J. Cowan, Inese I. Ivans, George M. Fuller, Scott Burles, Timothy C. Beers, James E. Lawler. 2000-03-07. Evidence of Multiple r-Process Sites in the Early Galaxy: New Observations of CS 22892-052. https://doi.org/10.1086/312631

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