Probing quarkyonic matter in neutron stars with the Bayesian nuclear-physics multimessenger astrophysics framework

Journal Article · 27 February 2024 · Physical Review. C

DOI: https://doi.org/10.1103/physrevc.109.025807 · OSTI ID:2338091

Pang, Peter T. H.  ^[1]; Sivertsen, Lars  ^[2]; Somasundaram, Rahul  ^[3]; Dietrich, Tim  ^[4]; Sen, Srimoyee  ^[2]; Tews, Ingo  ^[5]; Coughlin, Michael W.  ^[6]; Van Den Broeck, Chris ^[7]

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1. Nikhef Theory Group, Amsterdam (Netherlands); Utrecht University (Netherlands); Iowa State U
2. Iowa State Univ., Ames, IA (United States)
3. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Syracuse Univ., NY (United States)
4. Univ. of Potsdam (Germany); Max Planck Institute for Gravitational Physics, Potsdam (Germany)
5. Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
6. Univ. of Minnesota, Minneapolis, MN (United States)
7. Nikhef Theory Group, Amsterdam (Netherlands); Utrecht University (Netherlands)

The interiors of neutron stars contain matter at the highest densities realized in our Universe. Interestingly, theoretical studies of dense matter, in combination with the existence of two-solar-mass neutron stars, indicate that the speed of sound $$c_s$$ has to increase to values well above the conformal limit ($$c_s^2$$ = 1/3) before decreasing again at higher densities. Further, the decrease could be explained by either a strong first-order phase transition or a crossover transition from hadronic to quark matter. The latter scenario leads to a pronounced peak in the speed of sound, reaching values above the conformal limit, naturally explaining the inferred behavior. In this work, we use the nuclear-physics multimessenger astrophysics (NMMA) framework to compare predictions of the quarkyonic matter model with astrophysical observations of neutron stars, with the goal of constraining model parameters. Assuming quarkyonic matter to be realized within neutron stars, we find that there can be a significant amount of quarks inside the cores of neutron stars with masses in the two-solar-mass range, amounting to up to ≈0.13$$M$$_⊙, contributing ≈ 5.9% of the total mass. Furthermore, for the quarkyonic matter model investigated here, the radius of a 1.4$$M$$_⊙ neutron star would be $$13.44_{–1.54}^{+1.69}(13. 54_{–1.04}^{+1.02})$$ km, at 95% credibility, without (with) the inclusion of AT2017gfo.

• Research Organization: Iowa State Univ., Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR). Scientific Discovery through Advanced Computing (SciDAC); USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: SC0021892; AC52-06NA25396
• OSTI ID: 2338091
• Alternate ID(s): OSTI ID: 2474402; OSTI ID: 2511292
• Journal Information: Physical Review. C, Journal Name: Physical Review. C Journal Issue: 2 Vol. 109; ISSN 2469-9985
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English