Bulk viscosity in a hyperonic star and r-mode instability

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.82.025803· OSTI ID:21419470

Jha, T K ^[1]; Mishra, H; Sreekanth, V ^[1]

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1. Theoretical Physics Division, Physical Research Laboratory, Navrangpura, Ahmedabad-380 009 (India)

We consider a rotating neutron star with the presence of hyperons in its core. We use an equation of state in an effective chiral model within the relativistic mean-field approximation. We calculate the hyperonic bulk viscosity coefficient caused by nonleptonic weak interactions. By estimating the damping time scales of the dissipative processes, we investigate its role in the suppression of gravitationally driven instabilities in the r mode. We observe that r-mode instability remains very significant for hyperon core temperatures of around 10{sup 8} K, which results in a comparatively larger instability window. We find that such instability can reduce the angular velocity of the rapidly rotating star considerably up to {approx}0.04{Omega}{sub K}, with {Omega}{sub K} as the Keplerian angular velocity.

• OSTI ID: 21419470
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 82, Issue 2; Other Information: DOI: 10.1103/PhysRevC.82.025803; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ANGULAR VELOCITY
APPROXIMATIONS
CHIRALITY
COMPUTERIZED SIMULATION
DAMPING
EQUATIONS OF STATE
HYPERONS
INSTABILITY
MEAN-FIELD THEORY
NEUTRON STARS
RELATIVISTIC RANGE
VISCOSITY
WEAK HADRONIC DECAY
WEAK INTERACTIONS
BARYONS
BASIC INTERACTIONS
CALCULATION METHODS
DECAY
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
FERMIONS
HADRONS
INTERACTIONS
PARTICLE DECAY
PARTICLE PROPERTIES
SIMULATION
STARS
STRANGE PARTICLES
VELOCITY
WEAK PARTICLE DECAY