Nucleosynthesis in Outflows from Black Hole-Neutron Star Merger Disks With Full GR$\nu$RMHD

Abstract

Along with binary neutron star mergers, the in-spiral and merger of a black hole and a neutron star is a predicted site of $r$-process nucleosynthesis and associated kilonovae. For the right mass ratio, very large amounts of neutron rich material may become unbound from the post-merger accretion disk. We simulate a suite of four post-merger disks with full-transport general relativistic neutrino radiation magnetohydrodynamics. We find that the outflows from these disks are very close to the threshold conditions for robust $r$-process nucleosynthesis. For these conditions, the detailed properties of the outflow determine whether a full $r$-process can or cannot occur, implying that a wide range of observable phenomena are possible. We show that on average the disk outflow lanthanide fraction is suppressed relative to the solar isotopic pattern. In combination with the dynamical ejecta, these outflows imply a kilonova with both blue and red components.

References in corpus (23)

• The r-process of stellar nucleosynthesis: Astrophysics and nuclear physics achievements and mysteries
• Observation of gravitational waves from two neutron star-black hole coalescences
• Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers
• An enigmatic long-lasting gamma-ray burst not accompanied by a bright supernova
• A Kilonova Following a Long-Duration Gamma-Ray Burst at 350 Mpc
• A long-duration gamma-ray burst with a peculiar origin
• Black Hole-Neutron Star Mergers: Disk Mass Predictions
• Making a Short Gamma-Ray Burst from a Long one: Implications for the Nature of GRB 060614
• The intermediate r-process in core-collapse supernovae driven by the magneto-rotational instability
• Full Transport Model of GW170817-Like Disk Produces a Blue Kilonova
• Post-merger Mass Ejection of Low-mass Binary Neutron Stars
• Comprehensive study of mass ejection and nucleosynthesis in binary neutron star mergers leaving short-lived massive neutron stars
• General-relativistic neutrino-radiation magnetohydrodynamic simulation of seconds-long black hole-neutron star mergers
• Neutrino absorption and other physics dependencies in neutrino-cooled black-hole accretion disks
• The landscape of disk outflows from black hole - neutron star mergers
• Neutron-gamma competition for $\beta$-delayed neutron emission
• Estimation of M1 scissors mode strength for deformed nuclei in the medium to heavy mass region by statistical Hauser-Feshbach model calculations
• Imprints of r-process heating on fall-back accretion: distinguishing black hole-neutron star from double neutron star mergers
• Long-duration Gamma-ray Burst and Associated Kilonova Emission from Fast-spinning Black Hole--Neutron Star Mergers
• GRB 211227A as a peculiar long gamma-ray burst from compact star merger
• $\nu \text{bhlight}$: Radiation GRMHD for Neutrino-Driven Accretion Flows
• Long-term 3D-MHD Simulations of Black Hole Accretion Disks formed in Neutron Star Mergers
• HARM3D+NUC: A new method for simulating the post-merger phase of binary neutron star mergers with GRMHD, tabulated EOS and neutrino leakage

Cited by in corpus (8)

• The Science of the Einstein Telescope
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• Angle-dependent in-situ fast flavor transformations in post-neutron star merger disks
• Secular Outflows from Long-Lived Neutron Star Merger Remnants
• Chaos in Inhomogeneous Neutrino Fast Flavor Instability
• Element formation in radiation-hydrodynamics simulations of kilonovae
• Let there be neutrons! Hadronic photoproduction from a large flux of high-energy photons