Exotic bulk viscosity and its influence on neutron star r-modes
Authors: Chatterjee, Debarati; Bandyopadhyay, Debades
Source: Astrophysics and Space Science, Volume 308, Numbers 1-4, April 2007 , pp. 451-455(5)
Abstract:We investigate the effect of exotic matter in particular, hyperon matter on neutron star properties such as equation of state (EoS), mass-radius relationship and bulk viscosity. Here we construct equations of state within the framework of a relativistic field theoretical model. As hyperons are produced abundantly in dense matter, hyperon–hyperon interaction becomes important and is included in this model. Hyperon–hyperon interaction gives rise to a softer EoS which results in a smaller maximum mass neutron star compared with the case without the interaction. Next we compute the coefficient of bulk viscosity and the corresponding damping time scale due to the non-leptonic weak process including Λ hyperons. Further, we investigate the role of the bulk viscosity on gravitational radiation driven r-mode instability in a neutron star of given mass and temperature and find that the instability is effectively suppressed.
Document Type: Research Article
Affiliations: Email: firstname.lastname@example.org
Publication date: 2007-04-01