@article{72,
  author = {O. Just and A. Bauswein and R. Ardevol Pulpillo and S. Goriely and H .-Th.-Janka},
  title = {Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers},
  abstract = { <p>We present the first comprehensive study of r-process element nucleosynthesis in the ejecta of compact binary mergers (CBMs) and their relic black-hole (BH)-torus systems. The evolution of the BH-accretion tori is simulated for seconds with a Newtonian hydrodynamics code including viscosity effects, pseudo-Newtonian gravity for rotating BHs, and an energy-dependent two-moment closure scheme for the transport of electron neutrinos and antineutrinos. The investigated cases are guided by relativistic double neutron star (NS-NS) and NS-BH merger models, producing ~3-6 Msun BHs with rotation parameters of A~0.8 and tori of 0.03-0.3 Msun. Our nucleosynthesis analysis includes the dynamical (prompt) ejecta expelled during the CBM phase and the neutrino and viscously driven outflows of the relic BH-torus systems. While typically ~20-25\% of the initial accretion-torus mass are lost by viscously driven outflows, neutrino-powered winds contribute at most another ~1\%, but neutrino heating enhances the viscous ejecta significantly. Since BH-torus ejecta possess a wide distribution of electron fractions (0.1-0.6) and entropies, they produce heavy elements from A~80 up to the actinides, with relative contributions of A\&gt;130 nuclei being subdominant and sensitively dependent on BH and torus masses and the exact treatment of shear viscosity. The combined ejecta of CBM and BH-torus phases can reproduce the solar abundances amazingly well for A\&gt;90. Varying contributions of the torus ejecta might account for observed variations of lighter elements with 40\&lt;Z\&lt;56 relative to heavier ones, and a considerable reduction of the prompt ejecta compared to the torus ejecta, e.g. in highly asymmetric NS-BH mergers, might explain the composition of heavy-element deficient stars.</p>
 },
  year = {2015},
  journal = {MNRAS},
  volume = {448},
  chapter = {541},
  url = {https://arxiv.org/abs/1406.2687},
  language = {eng},
}