Magnetic Inclination Evolution of Accreting Neutron Stars in Intermediate/Low-Mass X-ray Binaries

Abstract

The magnetic inclination angle $\chi$, namely the angle between the spin and magnetic axes of a neutron star (NS), plays a vital role in its observational characteristics. However, there are few systematic investigations on its long-term evolution, especially for accreting NSs in binary systems. Applying the model of \citet{2021MNRAS.505.1775B} and the binary evolution code \mesa{}, we simultaneously simulate the evolution of the accretion rate, spin period, magnetic field, and magnetic inclination angle of accreting NSs in intermediate/low X-ray binaries (I/LMXBs). We show that the evolution of $\chi$ depends not only on the initial parameters of the binary systems, but also on the mass transfer history and the efficiency of pulsar loss. Based on the calculated results we present the characteristic distribution of $\chi$ for various types of systems including ultracompact X-ray binaries, binary millisecond pulsars, and ultraluminous X-ray sources, and discuss their possible observational implications.

12 pages, 7 figures, accepted for publication in ApJ

References in corpus (7)

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• Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
• Accretion funnels onto weakly magnetized young stars
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Cited by in corpus (7)

• A NICER view of the 1.4 solar-mass edge-on pulsar PSR J0614-3329
• Two-temperature accretion flows around strongly magnetized stars and their spectral analysis
• A short review of the pulsar magnetic inclination angles (II)
• The FAST Galactic Plane Pulsar Snapshot Survey: VII. Six millisecond pulsars in compact orbits with massive white dwarf companions
• Effect of irradiation on the spin of millisecond pulsars
• The spin-orbit alignment hypothesis in millisecond pulsars
• Evolution of Crab Pulsar: Magnetic Inclination Angle and Spin