Complete survey of r-process conditions: the (un-)robustness of the r-process(-es)

Fuente: arXiv
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Main Authors: Kuske, Jan, Arcones, Almudena, Reichert, Moritz
Format: Preprint
Published: 2025
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author Kuske, Jan
Arcones, Almudena
Reichert, Moritz
author_facet Kuske, Jan
Arcones, Almudena
Reichert, Moritz
contents Heavy elements are synthesized by the r-process in neutron star mergers and potentially in rare supernovae linked to strong magnetic fields. Expensive hydrodynamic simulations of these extreme environments are usually post-processed to calculate the nucleosynthesis. In contrast, here we follow a site-independent approach based on three key parameters: electron fraction, entropy, and expansion timescale. Our model reproduces the results based on hydrodynamic simulations. Moreover, the 120 000 astrophysical conditions analyzed allow us to systematically and generally explore the astrophysical conditions of the r-process, also beyond those found in current simulations. Our results show that a wide range of conditions produce very similar abundance patterns explaining the observed robustness of the r-process between the second and third peak. Furthermore, we cannot find a single condition that produces the full r-process from first to third peak. Instead, a superposition of at least two or three conditions or components is required to reproduce the typical r-process pattern as observed in the solar system and very old stars. The different final abundances are grouped into eight nucleosynthesis clusters, which can be used to select representative conditions for comparisons to observations and investigations of the nuclear physics input.
format Preprint
id arxiv_https___arxiv_org_abs_2506_00092
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Complete survey of r-process conditions: the (un-)robustness of the r-process(-es)
Kuske, Jan
Arcones, Almudena
Reichert, Moritz
High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
Heavy elements are synthesized by the r-process in neutron star mergers and potentially in rare supernovae linked to strong magnetic fields. Expensive hydrodynamic simulations of these extreme environments are usually post-processed to calculate the nucleosynthesis. In contrast, here we follow a site-independent approach based on three key parameters: electron fraction, entropy, and expansion timescale. Our model reproduces the results based on hydrodynamic simulations. Moreover, the 120 000 astrophysical conditions analyzed allow us to systematically and generally explore the astrophysical conditions of the r-process, also beyond those found in current simulations. Our results show that a wide range of conditions produce very similar abundance patterns explaining the observed robustness of the r-process between the second and third peak. Furthermore, we cannot find a single condition that produces the full r-process from first to third peak. Instead, a superposition of at least two or three conditions or components is required to reproduce the typical r-process pattern as observed in the solar system and very old stars. The different final abundances are grouped into eight nucleosynthesis clusters, which can be used to select representative conditions for comparisons to observations and investigations of the nuclear physics input.
title Complete survey of r-process conditions: the (un-)robustness of the r-process(-es)
topic High Energy Astrophysical Phenomena
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2506.00092