Temperature effects in pulsating superfluid neutron stars

Journal Article · Sun May 15 00:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.83.103008· OSTI ID:21502542

Kantor, Elena M ^[1]; Gusakov, Mikhail E ^[1]

---

1. Ioffe Physical Technical Institute, Polytekhnicheskaya 26, 194021 St.-Petersburg (Russian Federation)

We study the effects of finite stellar temperatures on the oscillations of superfluid neutron stars. The importance of these effects is illustrated with a simple example of a radially pulsating general relativistic star. Two main effects are taken into account: (i) temperature dependence of the entrainment matrix and (ii) the variation of the size of superfluid region with temperature. Four models are considered, which include either one or both of these two effects. Pulsation spectra are calculated for these models, and asymptotes for eigenfrequencies at temperatures close to critical temperature of neutron superfluidity are derived. It is demonstrated that models that allow for the temperature effect (ii) but disregard the effect (i), yield unrealistic results. Eigenfunctions for the normal- and superfluid-type pulsations are analyzed. It is shown that superfluid pulsation modes practically do not appear at the neutron-star surface and, therefore, can hardly be observed by measuring the modulation of the electromagnetic radiation from the star. The e-folding times for damping of pulsations due to the shear viscosity and nonequilibrium modified Urca processes are calculated and their asymptotes at temperatures close to the neutron critical temperature, are obtained. It is demonstrated that superfluid pulsation modes are damped by 1-3 orders of magnitude faster than normal modes.

• OSTI ID: 21502542
• Journal Information: Physical Review. D, Particles Fields, Vol. 83, Issue 10; Other Information: DOI: 10.1103/PhysRevD.83.103008; (c) 2011 American Institute of Physics; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CRITICAL TEMPERATURE
EIGENFREQUENCY
EIGENFUNCTIONS
ELECTROMAGNETIC RADIATION
ENTRAINMENT
NEUTRON STARS
NEUTRONS
OSCILLATIONS
PULSATIONS
RELATIVISTIC RANGE
SPECTRA
STARS
SUPERFLUIDITY
SURFACES
TEMPERATURE DEPENDENCE
BARYONS
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
FUNCTIONS
HADRONS
NUCLEONS
PHYSICAL PROPERTIES
RADIATIONS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE