Inertial oscillation modes of an inclined dipolar magnetosphere as a source of band-limited noise in X-ray pulsars
arXiv:2005.13508 · doi:10.1093/mnras/staa1544
Abstract
Magnetic fields of strongly magnetized stars can trap conducting matter due to frozen-in condition. In the force-free regime, the motion of the matter along the field lines may be considered in the "bead on a wire" approximation. Such a motion, if gravity and centrifugal forces are taken into account, has equilibrium points, some of which are stable. In most cases, stability is possible in about several per cent of the possible locations. Corresponding oscillation frequencies span the range from zero to of the spin frequency. We suggest that this variability mode may be excited in some X-ray pulsars during the outbursts and create the peaked broad-band noise component near the break frequency in the power density spectrum, as well as produce some of the quasi-periodic oscillation features in this frequency range. Existence of this variability does not require any changes in mass accretion rate and involves only a small amount of matter infiltrating from the disc and magnetic flow due to interchange instabilities.
arXiv commentaccepted to MNRAS; 6 pages, 5 figures
References in corpus (14)
- Mayavi: a package for 3D visualization of scientific data
- Spin-Up/Spin-Down of Magnetized Stars with Accretion Disks and Outflows
- Theory of quasi-spherical accretion in X-ray pulsars
- Magnetically Torqued Thin Accretion Disks
- Patterns of variability in Be/X-ray pulsars during giant outbursts
- Torque Enhancement, Spin Equilibrium, and Jet Power from Disk-Induced Opening of Pulsar Magnetic Fields
- Be/X-ray binaries and candidates: catalogue
- Quenching of the accretion disk strong aperiodic variability at the magnetospheric boundary
- Super-Eddington accretion onto a magnetized neutron star
- Shear-Driven Field-Line Opening and the Loss of a Force-Free Magnetostatic Equilibrium
- Magnetic field estimates for accreting neutron stars in massive binary systems and models of magnetic field decay
- Evidence for the radiation-pressure dominated accretion disk in bursting pulsar GRO J1744-28 using timing analysis
- Relativistic, Viscous, Radiation Hydrodynamic Simulations of Geometrically Thin Disks. II. Disk Variability
- Activity from the Be/X-ray binary system V0332+53 during its intermediate-luminosity outburst in 2008