The link between rare earth peak formation and the astrophysical site of the $r$ process

Abstract

The primary astrophysical source of the rare earth elements is the rapid neutron capture process ($r$ process). The rare earth peak that is seen in the solar $r$-process residuals has been proposed to originate as a pile-up of nuclei during the end of the $r$ process. We introduce a new method utilizing Monte Carlo studies of nuclear masses in the rare earth region, that includes self-consistently adjusting $\beta$-decay rates and neutron capture rates, to find the mass surfaces necessary for the formation of the rare earth peak. We demonstrate our method with two types of astrophysical scenarios, one corresponding conditions typical of core-collapse supernova winds and one corresponding to conditions typical of the ejection of the material from the tidal tails of neutron star mergers. In each type of astrophysical conditions, this method successfully locates a region of enhanced stability in the mass surface that is responsible for the rare earth peak. For each scenario, we find that the change in the mass surface has qualitatively different features, thus future measurements can shed light on the type of environment in which the $r$ process occurred.

5 pages, 4 figures, submitted

References in corpus (12)

• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers
• Magnetorotationally driven Supernovae as the origin of early galaxy $r$-process elements?
• R-process enrichment from a single event in an ancient dwarf galaxy
• Nucleosynthesis-relevant conditions in neutrino-driven supernova outflows. I. Spherically symmetric hydrodynamic simulations
• Detailed Chemical Abundances in the r-Process-Rich Ultra-Faint Dwarf Galaxy Reticulum 2
• On the Conditions for Neutron-Rich Gamma-Ray Burst Outflows
• Neutron Star Mergers as the Origin of r-Process Elements in the Galactic Halo Based on the Sub-halo Clustering Scenario
• Statistical Hauser-Feshbach theory with width fluctuation correction including direct reaction channels for neutron induced reaction at low energies
• A Long, Cold, Early r-process? Neutrino-induced Nucleosynthesis in He Shells Revisited
• Fission Cycling in a Supernova r-process
• A high-entropy wind r-process study based on nuclear-structure quantities from the new finite-range droplet model FRDM(2012)

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• From actinides to zinc: Using the full abundance pattern of the brightest star in Reticulum II to distinguish between different r-process sites
• The lanthanide fraction distribution in metal-poor stars: a test of neutron star mergers as the dominant r-process site
• Nucleosynthesis and observation of the heaviest elements
• Co-production of light and heavy $r$-process elements via fission deposition
• Reverse engineering nuclear properties from rare earth abundances in the $r$ process
• Markov Chain Monte Carlo Predictions of Neutron-rich Lanthanide Properties as a Probe of $r$-process Dynamics