Binary neutron star mergers of quark matter based nuclear equations of state

Atul Kedia,In-Saeng Suh,Hee Il Kim,Grant Mathews,W Liu,Y Wang,X Tang,S Zeng,B Guo

doi:10.1051/epjconf/202226011004

Atul Kedia, In-Saeng Suh + Show 7 more

Open Access

https://doi.org/10.1051/epjconf/202226011004

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Abstract

With observations of gravitational wave signals from binary neutron star mergers (BNSM) by LIGO-Virgo-KAGRA (LVK) Collaboration and NICER, the nuclear equation of state (EOS) is becoming increasingly testable by complementary numerical simulations. Numerous simulations currently explore the EOS at different density regimes for the constituent neutron stars speciﬁcally narrowing the uncertainty in the sub-nuclear densities. In this paper we summarize the three-dimensional general relativistic-hydrodynamics based simulations of BNSMs for EOSs with a speciﬁc emphasis on the quark matter EOS at the highest densities.

Highlights

Neutron stars are ideal locations to probe the properties of matter at the highest density
The LIGO analysis [1, 3] of the tidal polarizability [4, 5] deduced from post-Newtonian dynamics implies that the radius of the stars of 1.4 M⊙ is in the range 10.5 km ≤ R ≤ 13.3 km, which has placed tight constrains on the equation of state (EOS) for nuclear matter as the stars approach merger
To describe the evolution of matter in a closed form, the hydrodynamics equations require an additional constraint that relates the various state variables of the matter, i.e. pressure, density, electron fraction, chemical potentials, etc. in a neutron star. [14, 15] Constraints on the low density equation of state (EOS) have been placed by aLIGO based upon the tidal polarizability deduced from the chirp associated with event GW170817. [1, 3] the EOS at higher densities attained during a binary neutron star merger must include the consequences of a transition between hadronic matter and quark matter

Summary

Introduction

Neutron stars are ideal locations to probe the properties of matter at the highest density. The microphysics of nuclear interactions in a neutron star are reflected in its large structural features like its mass-radius relation. These interactions modulate the evolution of neutronstar binary systems. The first detection of gravitational waves from the binary neutron star merger GW170817 by the LIGO-Virgo Collaboration and the pulsar PSR J0740 by NICER have provided new insights into the form and structure of dense neutronstar matter. The reason to be excited about this, is that the detection of the gravitational radiation during the postmerger could be used as a sensitive probe of both the order of the quarkhadron phase transition and the properties of matter in the non-perturbative regime of QCD. There is a suggestion in the literature (see Refs. [11, 12]) of post merger energy output in gravitational radiation from the GW170817 event that appears to be an extended ringdown (see Ref. [13].) In Ref. [12] it was hypothesized that such extended emission might result from spin down of a magnetar

Dense matter Equation of State

Gravitational Waves and Power Spectral Density

Conclusion