High-entropy ejections from magnetized proto-neutron star winds: implications for heavy element nucleosynthesis

Abstract

Although initially thought to be promising for production of the r-process nuclei, standard models of neutrino-heated winds from proto-neutron stars (PNSs) do not reach the requisite neutron-to-seed ratio for production of the lanthanides and actinides. However, the abundance distribution created by the r-, rp-, or $\nu p$-processes in PNS winds depends sensitively on the entropy and dynamical expansion timescale of the flow, which may be strongly affected by high magnetic fields. Here, we present results from magnetohydrodynamic simulations of non-rotating neutrino-heated PNS winds with strong dipole magnetic fields from $10^{14}-10^{16}$ G, and assess their role in altering the conditions for nucleosynthesis. The strong field forms a closed zone and helmet streamer configuration at the equator, with episodic dynamical mass ejections in toroidal plasmoids. We find dramatically enhanced entropy in these regions and conditions favorable for third-peak r-process nucleosynthesis if the wind is neutron-rich. If instead the wind is proton-rich, the conditions will affect the abundances from the $\nu p$-process. We quantify the distribution of ejected matter in entropy and dynamical expansion timescale, and the critical magnetic field strength required to affect the entropy. For $B\gtrsim 10^{15}$ G, we find that $\gtrsim 10^{-6}$ M${}_{\odot }$ and up to $\sim 10^{-5}$ M${}_{\odot }$ of high entropy material is ejected per highly-magnetized neutron star birth in the wind phase, providing a mechanism for prompt heavy element enrichment of the universe. Former binary companions identified within (magnetar-hosting) supernova remnants, the remnants themselves, and runaway stars may exhibit overabundances. We provide a comparison with a semi-analytic model of plasmoid eruption and discuss implications and extensions.

accepted to MNRAS

References in corpus (12)

• Magnetorotationally driven Supernovae as the origin of early galaxy $r$-process elements?
• Simulation of Coherent Non-Linear Neutrino Flavor Transformation in the Supernova Environment I: Correlated Neutrino Trajectories
• The rp-Process in Neutrino-driven Winds
• The intermediate r-process in core-collapse supernovae driven by the magneto-rotational instability
• Supernova remnant energetics and magnetars: no evidence in favour of millisecond proto-neutron stars
• Relativistic MHD Winds from Rotating Neutron Stars
• Relativistic Jets and Long-Duration Gamma-ray Bursts from the Birth of Magnetars
• On the Conditions for Neutron-Rich Gamma-Ray Burst Outflows
• On The Intrinsic Diversity of Type II-Plateau Supernovae
• Magnetar-energized supernova explosions and GRB-jets
• On the origin of the lightest Molybdenum isotopes
• Neutrino-heated winds from rotating proto-magnetars

Cited by in corpus (18)

• Collapsars as a major source of r-process elements
• Neutron Star Mergers Might not be the Only Source of r-Process Elements in the Milky Way
• A magnetar origin for the kilonova ejecta in GW170817
• r-Process Nucleosynthesis: Connecting Rare-Isotope Beam Facilities with the Cosmos
• Neutron star mergers and rare core-collapse supernovae as sources of r-process enrichment in simulated galaxies
• Stochastic Chemical Evolution of Galactic Subhalos and the Origin of r-Process Elements
• On the Origin of the Early Solar System Radioactivities. Problems with the AGB and Massive Star Scenarios
• Signatures of R-process Enrichment in Supernovae from Collapsars
• The impact of natal kicks on galactic r-process enrichment by neutron star mergers
• Evidence for r-process delay in very metal-poor stars
• The Early Evolution of Magnetar Rotation I: Slowly Rotating "Normal" Magnetars
• Dynamics of baryon ejection in magnetar giant flares: implications for radio afterglows, r-process nucleosynthesis, and fast radio bursts
• The Gaia-ESO survey: placing constraints on the origin of r-process elements
• Nucleosynthesis signatures of neutrino-driven winds from proto-neutron stars: a perspective from chemical evolution models
• Three-Dimensional General-Relativistic Simulations of Neutrino-Driven Winds from Rotating Proto-Neutron Stars
• r-Process Nucleosynthesis and Radioactively Powered Transients from Magnetar Giant Flares
• Proto-Neutron Star Convection and the Neutrino-Driven Wind: Implications for the r-Process
• Proto-Neutron Star Convection and the Neutrino-Driven Wind: Implications for the $\nu$p-Process