Maximum mass of non-rotating neutron star precisely inferred to be 2.25 solar masses

A examine led by Prof. Fan Yizhong from the Purple Mountain Observatory of the Chinese language Academy of Sciences has achieved important precision in figuring out the higher mass restrict for non-rotating neutron stars, a pivotal side within the examine of nuclear physics and astrophysics.

The researchers confirmed that the utmost gravitational mass of a non-rotating neutron star is roughly 2.25 solar plenty with an uncertainty of simply 0.07 solar mass. Their study is revealed in Bodily Assessment D.

The final word destiny of a large star is intricately linked to its mass. Stars lighter than eight solar plenty finish their life cycle as white dwarfs, supported by electron degeneracy strain with a well known higher mass restrict, the Chandrasekhar restrict, close to 1.4 solar plenty.

For stars heavier than eight however lighter than 25 solar plenty, neutron stars might be produced, which as a substitute, are primarily upheld by neutron degeneracy strain. For non-rotating neutron stars, there may be additionally a important gravitational mass (i.e., M_TOV) generally known as the Oppenheimer restrict, above which the neutron star will collapse right into a black hole.

Establishing a exact Oppenheimer restrict is sort of difficult. Solely unfastened bounds may be set primarily based on the primary precept. Many particular evaluations are strongly model-dependent. The ensuing M_TOV are various and the uncertainties are massive.

Prof. Fan’s workforce has refined the inference of M_TOV by incorporating sturdy multi-messenger observations and dependable nuclear physics knowledge, circumventing the uncertainties current in earlier fashions. This consists of leveraging current developments in mass/radius measurements from LIGO/Virgo gravitational-wave detectors and the Neutron star Inside Composition Explorer (NICER).

Specifically, they integrated the knowledge of the utmost mass cutoff inferred from the neutron star mass distribution and considerably narrowed the parameter space, resulting in an unprecedented precision within the inferred M_TOV. Three various equation of state (EoS) reconstruction fashions have been employed to mitigate potential systematic errors, yielding nearly an identical outcomes for M_TOV and the corresponding radius, which is 11.9 km with an uncertainty of 0.6 km in three impartial EoS reconstruction approaches.

The exact analysis of M_TOV carries profound implications for each nuclear physics and astrophysics. It signifies a reasonably stiff EoS for neutron star matter and means that the compact objects with plenty within the vary of roughly 2.5 to three.0 solar plenty, detected by LIGO/Virgo, usually tend to be the lightest black holes. Moreover, the merger remnants of binary neutron star methods exceeding a total mass of roughly 2.76 solar masses would collapse into black holes, whereas lighter methods would consequence within the formation of (supramassive) neutron stars.