Astrophysical Implications on Hyperon Couplings and Hyperon Star Properties with Relativistic Equations of States

Hyperons are essential constituents in the neutron star interior. The poorly known hyperonic interaction is a source of uncertainty for studying laboratory hypernuclei and neutron star observations. In this work, we perform Bayesian inference of phenomenological hyperon–nucleon interactions using the tidal deformability measurement of the GW170817 binary neutron star merger as detected by LIGO/Virgo and the mass–radius measurements of PSR J0030+0541 and PSR J0740+6620 as detected by NICER. The analysis is based on a set of stiff relativistic neutron star matter equation of states with hyperons from the relativistic mean-field theory, naturally fulfilling the causality requirement and empirical nuclear matter properties. We specifically utilize the strong correlation recently deduced between the scalar and vector meson–hyperon couplings, imposed by the measured Λ separation energy in single-Λ hypernuclei, and perform four different tests with or without the strong correlation. We find that the laboratory hypernuclear constraint ensures a large enough Λ–scalar–meson coupling to match the large vector coupling in hyperon star matter. When adopting the current most probable intervals of hyperon couplings from the joint analysis of laboratory and astrophysical data, we find the maximum mass of hyperon stars is at most 2.176−0.202+0.085M⊙ (68% credible interval) from the chosen set of stiff equation of states. The reduction of the stellar radius due to hyperons is quantified based on our analysis and various hyperon star properties are provided.

[1]  M. Cheoun,et al.  Asymmetric Nuclear Matter in Relativistic Mean-field Models with Isoscalar- and Isovector-meson Mixing , 2022, 2202.06468.

[2]  C. Providência,et al.  Relativistic Description of Dense Matter Equation of State and Compatibility with Neutron Star Observables: A Bayesian Approach , 2022, 2201.12552.

[3]  D. Logoteta.  Hyperons in Neutron Stars , 2021, Universe.

[4]  T. E. Riley,et al.  A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy , 2021, The Astrophysical Journal Letters.

[5]  I. Cognard,et al.  The Radius of PSR J0740+6620 from NICER and XMM-Newton Data , 2021, The Astrophysical Journal Letters.

[6]  G. Burgio,et al.  Neutron stars and the nuclear equation of state , 2021, 2105.03747.

[7]  B. W. Meyers,et al.  Refined Mass and Geometric Measurements of the High-mass PSR J0740+6620 , 2021, The Astrophysical Journal Letters.

[8]  Bing Zhang,et al.  Constraints on the Maximum Mass of Neutron Stars with a Quark Core from GW170817 and NICER PSR J0030+0451 Data , 2021, The Astrophysical Journal.

[9]  P. Lasky,et al.  A scalable random forest regressor for combining neutron-star equation of state measurements: a case study with GW170817 and GW190425 , 2020, Monthly Notices of the Royal Astronomical Society.

[10]  A. Li,et al.  Neutron star equation of state: Quark mean-field (QMF) modeling and applications , 2020, Journal of High Energy Astrophysics.

[11]  P. Char,et al.  Structure of Quark Star: A Comparative Analysis of Bayesian Inference and Neural Network Based Modeling , 2020, The Astrophysical Journal.

[12]  W. Long,et al.  Novel relativistic mean field Lagrangian guided by pseudo-spin symmetry restoration , 2020 .

[13]  P. K. Panda,et al.  GW190814: Gravitational Waves from the Coalescence of a 23 M$_\odot$ Black Hole with a 2.6 M$_\odot$ Compact Object , 2020, 2006.12611.

[14]  P. K. Panda,et al.  GW190425: Observation of a Compact Binary Coalescence with Total Mass ∼ 3.4 M⊙ , 2020 .

[15]  Keith C. Gendreau,et al.  A NICER View of PSR J0030+0451: Millisecond Pulsar Parameter Estimation , 2019, The Astrophysical Journal.

[16]  W. Ho,et al.  PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter , 2019, The Astrophysical Journal.

[17]  À. Ramos,et al.  Interplay between Delta Particles and Hyperons in Neutron Stars , 2019, The Astrophysical Journal.

[18]  R. Lynch,et al.  Relativistic Shapiro delay measurements of an extremely massive millisecond pulsar , 2019, Nature Astronomy.

[19]  Rory Smith,et al.  Bilby: Bayesian inference library , 2019 .

[20]  A. Sedrakian,et al.  Competition between delta isobars and hyperons and properties of compact stars , 2018, Physics Letters B.

[21]  J. Stone,et al.  Quark-Meson-Coupling (QMC) model for finite nuclei, nuclear matter and beyond , 2018, 1802.08368.

[22]  Daniel Foreman-Mackey,et al.  corner.py: Scatterplot matrices in Python , 2016, J. Open Source Softw..

[23]  Johannes Buchner,et al.  PyMultiNest: Python interface for MultiNest , 2016 .

[24]  T. Hatsuda,et al.  Hyperon puzzle, hadron-quark crossover and massive neutron stars , 2015, 1508.04861.

[25]  G. Colucci,et al.  Constraining hypernuclear density functional with Λ-hypernuclei and compact stars , 2014, 1406.0744.

[26]  R. Lynch,et al.  A Massive Pulsar in a Compact Relativistic Binary , 2013, Science.

[27]  G. Bruce Berriman,et al.  Astrophysics Source Code Library , 2012, ArXiv.

[28]  S. Ransom,et al.  Shapiro delay measurement of a two solar mass neutron star , 2010, 1010.5788.

[29]  T. Hinderer.  Tidal Love Numbers of Neutron Stars , 2007, 0711.2420.

[30]  Zuo Wei,et al.  Hyperon-hyperon interaction in relativistic mean field model , 2007 .

[31]  J. Lattimer,et al.  Neutron star observations: Prognosis for equation of state constraints , 2006, astro-ph/0612440.

[32]  D. Vretenar,et al.  Relativistic nuclear energy density functional constrained by low-energy QCD , 2005, nucl-th/0509040.

[33]  H. Tamura.  Spectroscopy of $\Lambda$ hypernuclei , 2005 .

[34]  M. Bejger,et al.  Hyperon softening of the EOS of dense matter and the spin evolution of isolated neutron stars , 2003, astro-ph/0311470.

[35]  S. Teukolsky,et al.  Delayed collapse of hot neutron stars to black holes via hadronic phase transitions , 1996 .

[36]  P. Ellis,et al.  Kaon condensation in neutron star matter with hyperons , 1995, nucl-th/9502033.

[37]  Yuichi Sugahara,et al.  Relativistic mean-field theory for unstable nuclei with non-linear σ and ω terms , 1994 .

[38]  Serot,et al.  Quantum hadrodynamics , 1992 .

[39]  P. Reinhard.  REVIEW ARTICLE: The relativistic mean-field description of nuclei and nuclear dynamics , 1989 .

[40]  P. Guichon.  A Possible Quark Mechanism for the Saturation of Nuclear Matter , 1988 .

[41]  J. Walecka.  A theory of highly condensed matter , 1974 .

[42]  J. Negele,et al.  Neutron star matter at sub-nuclear densities , 1973 .

[43]  G. Baym,et al.  The Ground state of matter at high densities: Equation of state and stellar models , 1971 .

[44]  A. Cameron.  Pycnonuclear Reations and Nova Explosions. , 1959 .