Nucleosynthesis in the Early Galaxy
Abstract
Recent observations of r-process-enriched metal-poor star abundances reveal a nonuniform abundance pattern for elements Z<=47. Based on noncorrelation trends between elemental abundances as a function of Eu richness in a large sample of metal-poor stars, it is shown that the mixing of a consistent and robust light element primary process (LEPP) and the r-process pattern found in r-II metal-poor stars explains such apparent nonuniformity. Furthermore, we derive the abundance pattern of the LEPP from observation and show that it is consistent with a missing component in the solar abundances when using a recent s-process model. As the astrophysical site of the LEPP is not known, we explore the possibility of a neutron-capture process within a site-independent approach. It is suggested that scenarios with neutron densities nn<=1013 cm-3 or in the range nn>=1024 cm-3 best explain the observations.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2007
- DOI:
- 10.1086/523084
- arXiv:
- arXiv:0709.0417
- Bibcode:
- 2007ApJ...671.1685M
- Keywords:
-
- Galaxy: Abundances;
- Nuclear Reactions;
- Nucleosynthesis;
- Abundances;
- Stars: Formation;
- Astrophysics
- E-Print:
- 28 pages, 7 Postscript figures. To be published in The Astrophysical Journal