Warping modes in discs around accreting neutron stars

H. Meheut (1) , Michel Tagger (1, 2)

1 APC (UMR_7164) - AstroParticule et Cosmologie
2 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace

The origin and stability of a thin sheet of plasma in the magnetosphere of an accreting neutron star are investigated. First, the radial extension of such a magnetospheric disc is explored. Then a mechanism for magnetospheric accretion is proposed, reconsidering the bending wave explored by Agapitou, Papaloizou & Terquem, that was found to be stable in ideal magnetohydrodynamics. We show that this warping becomes unstable and can reach high amplitudes, in a variant of Pringle's radiation-driven model for the warping of active galactic nucleus accretion discs. Finally, we discuss how this mechanism might give a clue to explain the observed X-ray kilohertz quasi-periodic oscillation of neutron star binaries.

Mots clés: accretion; accretion discs; instabilities; MHD; stars: neutron; Astrophysics - High Energy Astrophysical Phenomena

Domaines: Planète et Univers [physics]

H. Meheut, Michel Tagger. Warping modes in discs around accreting neutron stars. Monthly Notices of the Royal Astronomical Society, 2009, 399, pp.794-800. ⟨10.1111/j.1365-2966.2009.15311.x⟩. ⟨insu-03611754⟩