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Astrophysical and Theoretical Physics Implications from Multimessenger Neutron Star Observations
Hector O Silva1,2, A Miguel Holgado3,4,5, Alejandro Cárdenas-Avendaño2,6
1Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Am Mühlenberg 1, D-14476 Potsdam, Germany.
Physical Review Letters
|May 21, 2021
Summary
NICER data reveals neutron star properties like moment of inertia, crucial for testing general relativity. This enables a new, equation-of-state-insensitive test of Einstein
Area of Science:
- Multi-messenger astrophysics
- Neutron star physics
- Gravitational physics
Background:
- Neutron stars are extreme laboratories for physics, with properties dependent on the equation of state of supranuclear matter.
- Previous measurements of neutron star properties were limited by the unknown equation of state.
- The Neutron Star Interior Composition Explorer (NICER) provides precise measurements of neutron star mass and radius.
Purpose of the Study:
- To infer the moment of inertia, quadrupole moment, and surface eccentricity of an isolated neutron star.
- To forecast the moment of inertia for neutron star A in the J0737-3039 binary.
- To perform the first theory-agnostic and equation-of-state-insensitive test of general relativity.
Main Methods:
- Utilizing NICER's measurements of the mass and equatorial radius of PSR J0030+0451.
- Employing relations between neutron star properties that are insensitive to the equation of state.
- Combining inferred properties with LIGO/Virgo tidal Love number measurements for the general relativity test.
Main Results:
- First-time inference of isolated neutron star moment of inertia, quadrupole moment, and surface eccentricity.
- Forecasted moment of inertia for neutron star A in J0737-3039.
- Established the first equation-of-state-insensitive test of general relativity, yielding the most stringent constraint on gravitational parity violation to date.
Conclusions:
- NICER observations enable novel constraints on neutron star properties and fundamental physics.
- The developed test provides a powerful tool for probing general relativity in the strong-field regime.
- Future multimessenger neutron star observations will further refine tests of fundamental physics and general relativity.
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