Why do fast-spinning accreting neutron stars evade the r-mode instability? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Why do fast-spinning accreting neutron stars evade the r-mode instability?
Plain
Theory says certain sloshing oscillations called r-modes should grow on their own in fast-spinning neutron stars, radiate gravitational waves and slow the stars down. Yet many observed stars spin fast in the region where this should happen.
Precise · changed · core
Revision 1: With standard shear and bulk viscosity, low-mass X-ray binaries spinning at $300\ \text{to}\ 700\ \mathrm{Hz}$ with inferred core temperatures of about $1e8\ \mathrm{K}$ lie inside the r-mode instability window. Determine the extra damping (viscous crust-core boundary layer, hyperon or quark bulk viscosity, superfluid mutual friction, resonances) or the low saturation amplitude that reconciles theory with the observed spin and temperature distribution.
Revision 2: With standard shear and bulk viscosity, low-mass X-ray binaries spinning at $300\ \text{to}\ 700\ \mathrm{Hz}$ with inferred core temperatures of about $10^{8}\ \mathrm{K}$ lie inside the r-mode instability window. Determine the extra damping (viscous crust-core boundary layer, hyperon or quark bulk viscosity, superfluid mutual friction, resonances) or the low saturation amplitude that reconciles theory with the observed spin and temperature distribution.
Settled by
A calculation of r-mode damping and nonlinear saturation in realistic stellar models that places the observed systems outside the window or predicts their spin-temperature distribution.
Kind
phenomenon
Answer type
mechanism
References
(empty)
Literature status
open
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