Viscous damping of r-modes and emission of gravitational waves

• Published in: Pramāṇa Vol. 99; no. 1
• Main Authors: Atta, Debasis, Basu, D N
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 20.02.2025; Springer Nature B.V
• Subjects: Astronomy; Astrophysics and Astroparticles; Boundary layers; Critical frequencies; Equations of state; Gravitational waves; Magnetic properties; Mathematical analysis; Muons; Neutron stars; Nuclear matter; Observations and Techniques; Physics; Physics and Astronomy; Pulsars; Tensors; Viscous damping; crustal moment of inertia; 04.40.Dg; core–crust transition; 26.60.−c; 04.30.−w; Nuclear equation of state; 21.30.Fe; R-mode instability; 26.60.Dd; 21.65.−f; 26.60.Gj; 97.60.Jd; pulsars
• ISSN: 0973-7111; 0304-4289; 0973-7111
• DOI: 10.1007/s12043-025-02897-5

The Rossby mode (r-mode) perturbation in pulsars as a steady gravitational wave source has been explored. The effect of a rigid crust on viscous damping and dissipation rate in the boundary layer between the fluid core and the crust has been studied. The intensity of the emitted GWs in terms of the strain tensor amplitude has been estimated with the approximation of slow rotation using equation of state derived from the APR and Skyrme effective interactions with Brussels–Montreal parameter sets. The core of the neutron star has been considered to be β -equilibrated nuclear matter containing neutrons, protons, electrons and muons, surrounded by a solid crust. Calculations have been made for critical frequencies, time evolution and rate of change of the spin frequencies across a broad spectrum of pulsar masses.