TY - JOUR

T1 - Non-radial oscillations of the magnetized rotating stars with purely toroidal magnetic fields

AU - Asai, Hidetaka

AU - Lee, Umin

AU - Yoshida, Shijun

N1 - Publisher Copyright:
© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.

PY - 2015/3/21

Y1 - 2015/3/21

N2 - We calculate non-axisymmetric oscillations of uniformly rotating polytropes magnetized with a purely toroidal magnetic field, taking account of the effects of the deformation due to the magnetic field. As for rotation, we consider only the effects of Coriolis force on the oscillation modes, ignoring those of the centrifugal force, that is, of the rotational deformation of the star. Since separation of variables is not possible for the oscillation of rotatingmagnetized stars, we employ finite series expansions for the perturbations using spherical harmonic functions. We calculate magnetically modified normal modes such as g-, f-, p-, r-, and inertial modes. In the lowest order, the frequency shifts produced by the magnetic field scale with the square of the characteristic Alfvén frequency. As a measure of the effects of the magnetic field, we calculate the proportionality constant for the frequency shifts for various oscillation modes. We find that the effects of the deformation are significant for high frequency modes such as fand p-modes but unimportant for low-frequency modes such as g-, r-, and inertial modes.

AB - We calculate non-axisymmetric oscillations of uniformly rotating polytropes magnetized with a purely toroidal magnetic field, taking account of the effects of the deformation due to the magnetic field. As for rotation, we consider only the effects of Coriolis force on the oscillation modes, ignoring those of the centrifugal force, that is, of the rotational deformation of the star. Since separation of variables is not possible for the oscillation of rotatingmagnetized stars, we employ finite series expansions for the perturbations using spherical harmonic functions. We calculate magnetically modified normal modes such as g-, f-, p-, r-, and inertial modes. In the lowest order, the frequency shifts produced by the magnetic field scale with the square of the characteristic Alfvén frequency. As a measure of the effects of the magnetic field, we calculate the proportionality constant for the frequency shifts for various oscillation modes. We find that the effects of the deformation are significant for high frequency modes such as fand p-modes but unimportant for low-frequency modes such as g-, r-, and inertial modes.

KW - Stars: magnetic field

KW - Stars: neutron

KW - Stars: oscillations

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U2 - 10.1093/mnras/stv538

DO - 10.1093/mnras/stv538

M3 - Article

AN - SCOPUS:84930013731

SN - 0035-8711

VL - 449

SP - 3620

EP - 3634

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 4

ER -