On the torque reversals of 4U 1626--67
arXiv:2110.15392 · doi:10.1051/0004-6361/202141772
Abstract
We have investigated the detailed torque-reversal behavior of 4U 1626--67 in the framework of the recently developed comprehensive model of the inner disk radius and torque calculations for neutron stars accreting from geometrically thin disks. The model can reproduce the torque -- X-ray luminosity relation across the torque reversals of 4U 1626--67. Our results imply that: (1) rotational equilibrium is reached when the inner disk radius equals the co-rotation radius, , while the conventional Alfven radius is greater than and close to , (2) both spin-up and spin-down torques are operating on either side of torque reversal, (3) with increasing accretion rate the spin-up torque associated with accretion onto the star gradually dominates the spin-down torque exerted by the disk. The torque reversals are the natural outcome of transitions between the well-defined weak-propeller and spin-up phases of the star with a stable geometrically thin accretion disk.
arXiv comment5 pages, 2 figures, accepted for publication in A&A
References in corpus (39)
- Observations of Accreting Pulsars
- A Radio Pulsar/X-ray Binary Link
- Swings between rotation and accretion power in a millisecond binary pulsar
- Magnetic Fields of Accreting X-Ray Pulsars with the Rossi X-Ray Timing Explorer
- X-Ray Flares and Mass Outflows Driven by Magnetic Interaction between a Protostar and its Surrounding Disk
- Spin-Up/Spin-Down of Magnetized Stars with Accretion Disks and Outflows
- A state change in the low-mass X-ray binary XSS J12270-4859
- Warped accretion discs and the long periods in X-ray binaries
- "Propeller" Regime of Disk Accretion to Rapidly Rotating Stars
- Magnetic propeller outflows
- Turbulent resistivity driven by the magnetorotational instability
- High-Speed Optical Photometry of the Ultracompact X-ray Binary 4U 1626-67
- X-ray coherent pulsations during a sub-luminous accretion disk state of the transitional millisecond pulsar XSS J12270-4859
- On the Correlation of Torque and Luminosity in GX 1+4
- Double-Peaked X-Ray Lines from the Oxygen/Neon-Rich Accretion Disk in 4U1626-67
- On the Dramatic Spin-up/Spin-down Torque Reversals in Accreting Pulsars
- BeppoSAX observation of 4U1626-67: Discovery of an absorption cyclotron resonance feature
- Timing Observations of PSR J1023+0038 During a Low-Mass X-ray Binary State
- Transitional millisecond pulsars
- New Torque Reversal and Spin-Up of 4u 1626- 67 Observed by Fermi/GBM and Swift/BAT
- On the spin-up/spin-down transitions in accreting X-ray binaries
- Theory of Disk Accretion onto Magnetic Stars
- Warped Disks as a Possible Origin of Torque Reversals in Accretion-Powered Pulsars
- 4U 1626-67 as seen by Suzaku before and after the 2008 torque reversal
- Accretion torque on magnetized neutron stars
- Partial Field Opening and Current Sheet Formation in the Disk Magnetosphere
- Torque Reversal in Accretion-Powered X-ray Pulsars
- Torque reversals and pulse profile of the pulsar 4U 1626-67
- Application of the Ghosh & Lamb Relation to the Spin-up/down Behavior in the X-ray Binary Pulsar 4U 1626-67
- A broadband self-consistent modelling of the X-ray spectrum of 4U 1626--67
- Recent Torque Reversal of 4U 1907+09
- Luminosity dependent change of the emission diagram in the X-ray pulsar 4U 1626-67
- Accretion And Propeller Torque In The Spin-down Phase Of Neutron Stars: The Case Of Transitional Millisecond Pulsar PSR J1023+0038
- Spectral Transition and Torque Reversal in X-ray Pulsar 4U 1626-67
- Pulse phase dependence of emission lines in the X-ray pulsar 4U 1626-67
- On the Torque Reversals of Accreting Neutron Stars
- Constraints on the disc-magnetosphere interaction in accreting pulsar 4U 1626--67
- On the peculiar torque reversals and the X-ray luminosity history of the accretion-powered X-ray pulsar 4U 1626--67
- Chandra/LETGS Studies of the Collisional Plasma in 4U 1626-67