The r-Process: History, Required Conditions, Astrophysical Sites, and Observations
Abstract
This review of the rapid-neutron-capture (i.e. r-) process starts with determining the Solar System r-abundance pattern via first obtaining (and subtracting) the contribution from the slow-neutron capture (s-) process. We emphasize the extensive work in this area by our late colleague Roberto Gallino and continue in an overview, concentrating on attempts to reproduce the solar r-process pattern with historical site-independent approaches, based on nuclear physics far from stability. In a second step we address the existing proposals for astrophysical sites. Among stellar observations we start with available observations of individual events before analyzing low-metallicity stars, which witness r-process contributions in the early Galaxy. We conclude with a comparison of observations and model predictions, focusing on our present ability to identify the responsible individual astrophysical sites by their imprint in Galactic evolution.
Cite
@article{arxiv.2601.17246,
title = {The r-Process: History, Required Conditions, Astrophysical Sites, and Observations},
author = {Friedrich-Karl Thielemann and John J. Cowan},
journal= {arXiv preprint arXiv:2601.17246},
year = {2026}
}
Comments
This is an invited review for the special issue of The European Physical Journal A, titled "About Stars and Nuclei: Honoring the Legacy of Roberto Gallino". This is the final accepted version, but written in "Astronomy Style" (i.e. with named references rather than numbered references as in the EPJA)