Bayesian Exploration of Phenomenological EoS of Neutron/Hybrid Stars with Recent Observations

Journal Article · Thu Feb 02 00:00:00 UTC 2023 · Particles

DOI: https://doi.org/10.3390/particles6010011 · OSTI ID:1974190

Chimanski, Emanuel V.  ^[1]; Lobato, Ronaldo V.  ^[2]; Goncalves, Andre R.  ^[3]; Bertulani, Carlos A.  ^[4]

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1. Brookhaven National Lab. (BNL), Upton, NY (United States). National Nuclear Data Center (NNDC)
2. Texas A & M Univ., Commerce, TX (United States); University of the Andes (Colombia)
3. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
4. Texas A & M Univ., Commerce, TX (United States)

The description of the stellar interior of compact stars remains as a big challenge for the nuclear astrophysics community. The consolidated knowledge is restricted to density regions around the saturation of hadronic matter ρ₀=2.8 × 10¹⁴ g cm^-3, regimes where our nuclear models are successfully applied. As one moves towards higher densities and extreme conditions up to the quark/gluons deconfinement, little can be said about the microphysics of the equation of state (EoS). Here, we employ a Markov Chain Monte Carlo (MCMC) strategy to access the variability at high density regions of polytropic piecewise models for neutron star (NS) EoS or possible hybrid stars, i.e., a NS with a small quark-matter core. With a fixed description of the hadronic matter for low density, below the nuclear saturation density, we explore a variety of models for the high density regimes leading to stellar masses near to 2.5 M_⊙, in accordance with the observations of massive pulsars. The models are constrained, including the observation of the merger of neutrons stars from VIRGO-LIGO and with the pulsar observed by NICER. In addition, we also discuss the possibility of the use of a Bayesian power regression model with heteroscedastic error. The set of EoS from the Laser Interferometer Gravitational-Wave Observatory (LIGO) was used as input and treated as the data set for the testing case.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC02-98CH10886; FG02-08ER41533; SC0012704
• OSTI ID: 1974190
• Report Number(s): BNL-224285-2023-JAAM
• Journal Information: Particles, Journal Name: Particles Journal Issue: 1 Vol. 6; ISSN 2571-712X
• Publisher: MDPICopyright Statement
• Country of Publication: United States
• Language: English