The maximal gravitational mass of nonrotating neutron stars (MTOVβ)
is one of the key parameters of compact objects and only loose bounds can be
set based on the first principle. With reliable measurements of the masses
and/or radii of the neutron stars, MTOVβ can be robustly inferred from
either the mass distribution of these objects or the reconstruction of the
equation of state (EoS) of the very dense matter. For the first time we take
the advantages of both two approaches to have a precise inference of MTOVβ=2.25β0.07+0.08βΒ Mββ (68.3% credibility), with the updated
neutron star mass measurement sample, the mass-tidal deformability data of
GW170817, the mass-radius data of PSR J0030+0451 and PSR J0740+6620, as well as
the theoretical information from the chiral effective theory (ΟEFT) and
perturbative quantum chromodynamics (pQCD) at low and very high energy
densities, respectively. This narrow credible range is benefited from the
suppression of the high MTOVβ by the pQCD constraint and the exclusion
of the low MTOVβ by the mass function. Three different EoS
reconstruction methods are adopted separately, and the resulting MTOVβ
are found to be almost identical. This precisely evaluated MTOVβ
suggests that the EoS of neutron star matter is just moderately stiff and the
βΌ2.5β3Mββ compact objects detected by the second generation
gravitational wave detectors are most likely the lightest black holes.Comment: 12 pages, 6 figure