The Role of Fission in Neutron Star Mergers and Its Impact on the r-Process Peaks
Loading...
Files
[The Role of Fission in Neutron Star Mergers and its Impact on the r-Process Peaks]
Authors
Eichler, Marius
Arcones, Almudena
Kelic, Alexandra
Korobkin, Oleg
Langanke, Karlheinz
Marketin, Tomislav
Martinez-Pinedo, Gabriel
Panov, Igor
Rauscher, Thomas
Rosswog, Stephan
Author (Corporation)
Publication date
15.07.2015
Type of student thesis
Course of study
Type
01A - Journal article
Editors
Editor (Corporation)
Supervisor
Parent work
The Astrophysical Journal
Special issue
DOI of the original publication
Link
Related research data
Series
Series number
Volume
808
Issue / Number
1
Pages / Duration
13-43
Patent number
Publisher / Publishing institution
The American Astronomical Society
Place of publication / Event location
Washington
Edition
Version
Programming language
Assignee
Practice partner / Client
Abstract
Comparing observational abundance features with nucleosynthesis predictions of stellar evolution or explosion simulations can scrutinize two aspects: (a) the conditions in the astrophysical production site and (b) the quality of the nuclear physics input utilized. We test the abundance features of r-process nucleosynthesis calculations for the dynamical ejecta of neutron star merger simulations based on three different nuclear mass models: The Finite Range Droplet Model (FRDM), the (quenched version of the) Extended Thomas Fermi Model with Strutinsky Integral (ETFSI-Q), and the Hartree-Fock-Bogoliubov (HFB) mass model. We make use of corresponding fission barrier heights and compare the impact of four different fission fragment distribution models on the final r-process abundance distribution. In particular, we explore the abundance distribution in the second r-process peak and the rare-earth sub-peak as a function of mass models and fission fragment distributions, as well as the origin of a shift in the third r-process peak position. The latter has been noticed in a number of merger nucleosynthesis predictions. We show that the shift occurs during the r-process freeze-out when neutron captures and β-decays compete and an (n,γ)-(γ,n) equilibrium is not maintained anymore. During this phase neutrons originate mainly from fission of material above A = 240. We also investigate the role of β-decay half-lives from recent theoretical advances, which lead either to a smaller amount of fissioning nuclei during freeze-out or a faster (and thus earlier) release of fission neutrons, which can (partially) prevent this shift and has an impact on the second and rare-earth peak as well.
Keywords
nucleosynthesis, stars:neutron, r-process
Subject (DDC)
Event
Exhibition start date
Exhibition end date
Conference start date
Conference end date
Date of the last check
ISBN
ISSN
1538-4357
0004-637X
0004-637X
Language
English
Created during FHNW affiliation
Yes
Strategic action fields FHNW
Publication status
Published
Review
peer-reviewed
Open access category
License
Citation
Eichler, M., Arcones, A., Kelic, A., Korobkin, O., Langanke, K., Marketin, T., Martinez-Pinedo, G., Panov, I., Rauscher, T., Rosswog, S., Winteler, C., Zinner, N., & Thielemann, F.-K. (2015). The Role of Fission in Neutron Star Mergers and Its Impact on the r-Process Peaks. The Astrophysical Journal, 808(1), 13–43. https://doi.org/10.1088/0004-637X/808/1/30