Influence of nuclear physics inputs and astrophysical conditions on Th/U chronometer

TL;DR

This study investigates how nuclear physics inputs and astrophysical conditions affect Th/U chronometry, providing refined stellar age estimates and assessing uncertainties in r-process nucleosynthesis models.

Contribution

It offers a detailed analysis of the impact of nuclear mass uncertainties on Th/U chronometer and derives stellar ages using improved nuclear and stellar data.

Findings

Nuclear mass uncertainties can cause age estimate errors up to 2 Gyr.

Estimated ages of metal-poor stars are around 11.8 to 13.5 Gyr.

Results support the use of Th/U chronometry as an independent universe age check.

Abstract

The productions of thorium and uranium are key ingredients in $r$-process nucleo-cosmochronology. With the combination of improved nuclear and stellar data, we have made detailed investigations on the $r$-process abundance pattern in the very metal-poor halo stars based on the classical $r$-process approach. It is found that the results are almost independent of specified simulations to observed abundances. The influence from nuclear mass uncertainties on Th/U chronometer can approach 2 Gyr. Moreover, the ages of the metal-poor stars HE 1523-0901, CS 31082-001, and BD +17$^\circ$3248 are determined as $11.8\pm 3.7$, $13.5\pm 2.9$, and $10.9 \pm 2.9$ Gyr, respectively. The results can serve as an independent check for age estimate of the universe.