Magnetic angle evolution in accreting neutron stars

ABSTRACT The rotation of a magnetized accreting neutron star (NS) in binary system is described by its spin period and two angles: inclination α with respect to the orbital momentum magnetic angle χ between moment. Magnetospheric accretion spins NS up adjusts axis, decreasing nearly perfect alignment. Its effect upon more subtle relatively unstudied. In this work, we model evolution rigid spherical NS. We find that torque spinning may affect while both significantly deviate from zero, spin-up varies phase period. As axis being aligned torque, becomes misaligned axis. Under favourable conditions, increase Δχ ∼ 15°−20°. This orthogonalization be an important factor millisecond pulsars, as it partially compensates decrease potentially caused pulsar torques. If direction changes randomly time, wind-fed high-mass X-ray binaries, become involved non-linear random-walk evolution. ultimate attractor process bimodal distribution peaking at = 0° 90°.