Correlation Between U/Th and Pb/Os Abundance Ratios and its Application in Nuclear Cosmochronology

• Published in: The Astrophysical journal Vol. 988; no. 1; pp. 22 - 28
• Main Authors: Huang, Y. Y., Cui, Q. Q., Wu, X. H., Zhang, S. Q.
• Format: Journal Article
• Language: English
• Published: Philadelphia The American Astronomical Society 20.07.2025; IOP Publishing
• Subjects: Abundance; Background radiation; Correlation; Cosmic microwave background; Measuring instruments; Metallicity; Nuclear abundances; Nuclear astrophysics; R-process; Radioisotopes; Stellar ages; Thorium
• ISSN: 0004-637X; 1538-4357; 1538-4357
• DOI: 10.3847/1538-4357/ade390

The abundance ratios of radioactive elements U/Th and stable elements Pb/Os from the r -process are found to have a strong correlation. This correlation is quite robust with respect to astrophysical conditions. The U/Th–Pb/Os correlation is applied to provide customized initial abundance ratios U/Th from the observed abundance ratios Pb/Os for six r -process enhanced metal-poor stars. The ages of these six metal-poor stars are predicted by the U/Th chronometer, which are approximately between 11 and 15 Gyr. Their ages are compatible with the cosmic age of 13.8 billion years predicted from the cosmic microwave background radiation.