R-modes in neutron stars: Theory and observations

Abstract

In this article I will review the theory behind the gravitational wave driven r-mode instability in rapidly rotating neutron stars and discuss which constraints can be derived from observations of spins and temperatures in Low Mass X-ray Binaries. I will discuss how a standard, `minimal' neutron star model is not consistent with the data, and discuss some of the additional physical mechanisms that could reconcile theory with observations. In particular I will focus on additional forms of damping due to exotic cores and on strong mutual friction due to superfluid vortices cutting through superconducting flux tubes, and examine the repercussions these effects could have on the saturation amplitude of the mode. Finally I will also discuss the possibility that oscillations due to r-modes may have been recently observed in the X-ray light curves of two Low Mass X-ray Binaries.

17 pages

References in corpus (18)

• Color superconductivity in dense quark matter
• Maximum elastic deformations of compact stars with exotic equations of state
• Detecting gravitational wave emission from the known accreting neutron stars
• Spin Evolution of Accreting Neutron Stars: Nonlinear Development of the R-mode Instability
• Detecting gravitational waves from mountains on neutron stars in the Advanced Detector Era
• Are neutron stars with crystalline colour superconducting cores interesting for the LIGO experiment?
• Implications of an r-mode in XTE J1751-305: Mass, radius and spin evolution
• Ekman layer damping of r-modes revisited
• Discovery of a Neutron Star Oscillation Mode During a Superburst
• Viscosity of neutron star matter and $r$-modes in rotating pulsars
• Excitation of a nonradial mode in a millisecond X-ray pulsar XTE J1751-305
• On the oscillations of dissipative superfluid neutron stars
• Oscillations of Rapidly Rotating Superfluid Stars
• New possible class of neutron stars: hot and fast non-accreting rotators
• Non-radial oscillations of the magnetized rotating stars with purely toroidal magnetic fields
• Gravitational waves from rapidly rotating neutron stars
• Differential rotation and r-modes in magnetized neutron stars
• Probing dense matter in compact star cores with radio pulsar data

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• Deep learning for clustering of continuous gravitational wave candidates
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• Chandra studies of the globular cluster 47 Tucanae: A deeper X-ray source catalogue, five new X-ray counterparts to millisecond radio pulsars, and new constraints to r-mode instability window
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• Gravitational waves from mountains in newly born millisecond magnetars
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• Strengthening the bounds on the r-mode amplitude with X-ray observations of millisecond pulsars
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• Role of nucleon-nucleon correlation in transport coefficients and gravitational-wave-driven $r$-mode instability of neutron stars
• Optimizing the third generation of gravitational-wave observatories for Galactic astrophysics
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• Influence of the nuclear matter equation of state on the r-mode instability using the finite-range simple effective interaction
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• Resonance suppression of the r-mode instability in superfluid neutron stars: Accounting for muons and entrainment
• Instability windows of relativistic r-modes
• Astroseismology of neutron stars from gravitational waves in the limit of perfect measurement
• Stability of the neutron-proton-electron matter under strong magnetic fields: the covariant Vlasov approach
• Effect of Magnetic Fields on Urca Rates in Neutron Star Mergers
• Evolution of newborn rapidly rotating magnetars: effects of r-mode and fall-back accretion
• Search for continuous gravitational waves from HESS~J1427-608 with a hidden Markov model
• r-mode instability of neutron stars in low-mass X-ray binaries: effects of Fermi surface depletion and superfluidity of dense matter
• Radiation driven instability of rapidly rotating relativistic stars: criterion and evolution equations via multipolar expansion of gravitational waves
• Non-analytic behavior of the relativistic r-modes in slowly rotating neutron stars
• Long term evolution of CFS-unstable neutron stars and role of differential rotation on short time-scales
• Constraining the $f$-mode oscillations frequency in Neutron Stars through Universal Relations in the realm of Energy-Momentum Squared Gravity
• Observability of HOFNARs with SRG/eROSITA
• Simulating bulk viscosity in neutron stars. I. Formalism
• Radial Oscillations of Viscous Neutron Stars: Zero Diffusion Case
• Of Mountains and Molehills : Gravitational Waves from Neutron Stars
• Results from an Einstein@Home search for continuous gravitational waves from Cassiopeia A and Vela Jr. using LIGO O2 data
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• Observability of sharp phase transitions in neutron stars
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