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Astrophysics, High Energy Astrophysical Phenomena, astro-ph.HE,General Relativity and Quantum Cosmology, gr-qc,Nuclear Theory, nucl-th
Abstract:
Once further confirmed in future analyses, the radius and mass measurement of
HESS J1731-347 with $M=0.77^{+0.20}_{-0.17}~M_{\odot}$ and
$R=10.4^{+0.86}_{-0.78}~\rm km$ will be among the lightest and smallest compact
objects ever detected. This raises many questions about its nature and opens up
the window for different theories to explain such a measurement. In this
article, we use the information from Doroshenko et al. (2022) on the mass,
radius, and surface temperature together with the multimessenger observations
of neutron stars to investigate the possibility that HESS J1731-347 is one of
the lightest observed neutron star, a strange quark star, a hybrid star with an
early deconfinement phase transition, or a dark matter-admixed neutron star.
The nucleonic and quark matter are modeled within realistic equation of states
(EOSs) with a self-consistent calculation of the pairing gaps in quark matter.
By performing the joint analysis of the thermal evolution and mass-radius
constraint, we find evidence that within a 1$\sigma$ confidence level, HESS
J1731-347 is consistent with the neutron star scenario with the soft EOS as
well as with a strange and hybrid star with the early deconfinement phase
transition with a strong quark pairing and neutron star admixed with dark
matter.
