A Nuclear Equation of State Inferred from Stellar r-process Abundances

Abstract

Binary neutron star mergers (NSMs) have been confirmed as one source of the heaviest observable elements made by the rapid neutron-capture (r-) process. However, modeling NSM outflows -- from the total ejecta masses to their elemental yields -- depends on the unknown nuclear equation of state (EOS) that governs neutron-star structure. In this work, we derive a phenomenological EOS by assuming that NSMs are the dominant sources of the heavy element material in metal-poor stars with r-process abundance patterns. We start with a population synthesis model to obtain a population of merging neutron star binaries and calculate their EOS-dependent elemental yields. Under the assumption that these mergers were responsible for the majority of r-process elements in the metal-poor stars, we find parameters representing the EOS for which the theoretical NSM yields reproduce the derived abundances from observations of metal-poor stars. For our proof-of-concept assumptions, we find an EOS that is slightly softer than, but still in agreement with, current constraints, e.g., by the Neutron Star Interior Composition Explorer, with $R_{1.4}=12.25\pm 0.03$~km and $M_{\text{T}OV}$ of $2.17\pm 0.03$~M${}_{\odot }$(statistical uncertainties, neglecting modeling systematics).

11 pages, 8 figures

References in corpus (32)

• The NumPy array: a structure for efficient numerical computation
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Origin of the heavy elements in binary neutron-star mergers from a gravitational wave event
• A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
• Swope Supernova Survey 2017a (SSS17a), the Optical Counterpart to a Gravitational Wave Source
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. II. UV, Optical, and Near-IR Light Curves and Comparison to Kilonova Models
• Refined Mass and Geometric Measurements of the High-Mass PSR J0740+6620
• Light Curves of the Neutron Star Merger GW170817/SSS17a: Implications for R-Process Nucleosynthesis
• Constraining the Maximum Mass of Neutron Stars From Multi-Messenger Observations of GW170817
• Comprehensive nucleosynthesis analysis for ejecta of compact binary mergers
• Magnetorotationally driven Supernovae as the origin of early galaxy $r$-process elements?
• Double Compact Objects III: Gravitational Wave Detection Rates
• The Effect of Pair-Instability Mass Loss on Black Hole Mergers
• Electromagnetic Evidence that SSS17a is the Result of a Binary Neutron Star Merger
• Spectral Representations of Neutron-Star Equations of State
• An R-process enhanced star in the dwarf galaxy Tucana III
• The role of neutron star mergers in the chemical evolution of the Galactic halo
• The $R$-Process Alliance: Fourth Data Release from the Search for $r$-Process-Enhanced Stars in the Galactic Halo
• Neutron Star Mergers as the Origin of r-Process Elements in the Galactic Halo Based on the Sub-halo Clustering Scenario
• Kilonovae across the nuclear physics landscape: The impact of nuclear physics uncertainties on r-process-powered emission
• Modeling Kilonova Light Curves: Dependence on Nuclear Inputs
• The R-process Alliance: First Magellan/MIKE Release from the Southern Search for R-Process-enhanced Stars
• The Hamburg/ESO R-process Enhanced Star survey (HERES) X. HE 2252-4225, one more r-process enhanced and actinide-boost halo star
• High-resolution abundance analysis of very metal-poor r-I stars
• A low-mass binary neutron star: long-term ejecta evolution and kilonovae with weak blue emission
• Simulating Neutron Star Mergers as r-process Sources in Ultra Faint Dwarf Galaxies
• Implications of PREX-2 on the electric dipole polarizability of neutron rich nuclei
• Probing the production of actinides under different r-process conditions
• The role of weak interactions in dynamic ejecta from binary neutron star mergers
• Reverse engineering nuclear properties from rare earth abundances in the $r$ process
• The R-Process Alliance: Discovery of a low-alpha, r-Process-Enhanced Metal-Poor Star in the Galactic Halo
• Reconstructing Masses of Merging Neutron Stars from Stellar $R$-Process Abundance Signatures

Cited by in corpus (3)

• Can neutron star mergers alone explain the r-process enrichment of the Milky Way?
• A Bayesian inference of relativistic mean-field model for neutron star matter from observation of NICER and GW170817/AT2017gfo
• Equation of state of nuclear matter and neutron stars: Quark mean-field model versus relativistic mean-field model