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1.
The dynamics of the rotation of a two-component system in the core of a neutron star is analyzed within the framework of the
generai theory of relativity (GTR). A theory of the relaxation of the angular velocity of the Vela pulsar is developed with
allowance for GTR corrections. From a comparison of the theory with observational data on the Vela pulsar, the relative moments
and positions of the relaxation regions are found for one of the standard models of a neutron star. It is shown that the theory
agrees with observations and supports this model neutron star as an acceptable pulsar model.
Translated from Astrofizika, Vol. 43, No. 1, pp. 85-94, January–March, 2000. 相似文献
2.
D. M. Sedrakian 《Astrophysics》1997,40(3):260-266
Equations are obtained for the dynamics of the rotation of a two-component model neutron star within the framework of the
generai theory of relativity. It is shown that for steady rotation of the star’s normal component, Ωc = const, the angular velocity Ωs of the superfluid component depends on the coordinates and is Ωc + ω, where ω is the nondiagonal component of the metric tensor.
Translated from Astrofizika, Vol. 40, No. 3, pp. 403–412, August, 1997. 相似文献
3.
The dynamics of the rotation of a two-component system in a neutron star is considered within the framework of the general
theory of relativity. Equations for the angular velocities of the normal and superfluid components are obtained in the W approximation.
It is shown that the solutions of these equations can describe the relaxation of pulsar angular velocity after a glitch.
Translated from Astrofizika, Vol. 42, No. 1, pp. 89–100, January–March, 1999. 相似文献
4.
D. M. Sedrakian 《Astrophysics》2006,49(1):83-87
The electromagnetic properties of neutron stars (pulsars) are studied. It is shown that taking the presence of two angular
rotation velocities of the components of neutron stars and the first corrections to the general theory of relativity into
account in the equations of hydrodynamic equilibrium for the plasma and in Maxwell’s equations leads to the generation of
toroidal magnetic fields in the depths of a neutron star.
__________
Translated from Astrofizika, Vol. 49, No. 1, pp. 97–101 (February 2006). 相似文献
5.
M. V. Hairapetian 《Astrophysics》2000,43(4):458-462
A previously developed theory of the relaxation of a pulsar's angular velocity within the framework of general relativity is compared with observational data for the Vela pulsar on the basis of a quark model of a neutron star. The relative moments of inertia and the positions of relaxation regions are found. It is shown that the model of a neutron star containing normal quark matter is inconsistent with observations of the relaxation of pulsar angular velocity. 相似文献
6.
M. V. Hayrapetyan 《Astrophysics》2008,51(4):559-564
The gravitational radiation of a neutron star with a weakly coupled superfluid component is considered. It is assumed that
regions can exist in the star's core which rotate at substantially higher angular velocities than the observed angular velocities
of pulsars. A star of this sort has a quadrupole moment on the order of the maximum value for the neutron star configurations
that have been discussed, so it could be a powerful source of gravitational radiation for the planned Advanced LIGO detector.
Translated from Astrofizika, Vol. 51, No. 4, pp. 647–652 (November 2008). 相似文献
7.
The superconducting proton condensate in the “npe” phase of a neutron star is considered. It is shown to be a type II superconductor
in the outer layer of the “npe” phase and a type I superconductor in the inner layer. Relaxation times are found for elastic
scattering of normal relativistic electrons from the magnetic fields of proton vortex clusters in the case of a type II superconductor
and elastic scattering from the magnetic field at the center of a neutron vortex in the case of a superconductor of the first
kind. The dynamical relaxation times obtained for the angular velocity of the pulsar PSR 0833—45 vary, as a function of the
density of the layers taking part in the relaxation process, within a fairly wide range: from several hours to l09 years. This means that the characteristic times of variation of pulsar angular velocity may be observed to lie in the indicated
time range.
Translated from Astrofizika, Vol. 40, No. 4, op. 497–506, October–December, 1997. 相似文献
8.
The constraints on the properties of neutron star matter from the mass of neutron star PSR J1614-2230 are examined in the framework of the relativistic mean field theory. We find that there are little differences between the σ potentials of large mass neutron star and those of canonnical mass neutron star. For potentials of ω, ρ, neutrons and electrons, the values corresponding to the large mass neutron star are larger than those to the canonnical mass neutron star as the baryon number density is more than a certain value. We also find that for the relative particle number density of electrons, muons, neutrons and protons and the pressure of the neutron star, the values corresponding to the large mass neutron star are far larger than those to the canonnical mass neutron star. For the relative particle number density of hyperons Λ, Σ?, Σ0, Σ+ and Ξ?, the values corresponding to the large mass neutron star are far smaller than those to the canonnical mass neutron star. These mean that the larger mass of neutron star is more advantageous to the production of protons but is not advantageous to the production of hyperons. 相似文献
9.
The vortex structure of the “npe” phase of neutron stars with a 3P2 superfluid neutron condensate of Cooper pairs is discussed. It is shown that, as the star rotates, superfluid neutron vortex
filaments described by a unitary ordering parameter develop in the “npe” phase. The entrainment of superconducting protons
by the rotating superfluid neutrons is examined. The entrainment effect leads to the appearance of clusters of proton vortices
around each neutron vortex and generates a magnetic field on the order of 1012 G. 3P2 neutron vortex filaments combine with quark semi-superfluid vortex filaments at the boundary of the “npe” and “CFL” phases.
At the boundary of the “Aen” and “npe” phases, they combine with 1S0 neutron vortex filaments. In this way, a unified vortex structure is formed. The existence of this structure and its collective
elastic oscillations explain the observed oscillations in the angular rotation velocity of pulsars. 相似文献
10.
Bahodir B. Ahmedov 《Astrophysics and Space Science》2011,331(2):565-573
The general-relativistic Ohm’s law for a two-component plasma which includes the gravitomagnetic force terms even in the case
of quasi-neutrality has been derived. The equations that describe the electromagnetic processes in a plasma surrounding a
neutron star are obtained by using the general relativistic form of Maxwell equations in a geometry of slow rotating gravitational
object. In addition to the general-relativistic effect first discussed by Khanna and Camenzind (Astron. Astrophys. 307:665,
1996) we predict a mechanism of the generation of azimuthal current under the general relativistic effect of dragging of inertial
frames on radial current in a plasma around neutron star. The azimuthal current being proportional to the angular velocity
ω of the dragging of inertial frames can give valuable contribution on the evolution of the stellar magnetic field if ω exceeds 2.7×1017(n/σ) s−1 (n is the number density of the charged particles, σ is the conductivity of plasma). Thus in general relativity a rotating neutron star, embedded in plasma, can in principle
generate axial-symmetric magnetic fields even in axisymmetry. However, classical Cowling’s antidynamo theorem, according to
which a stationary axial-symmetric magnetic field can not be sustained against ohmic diffusion, has to be hold in the general-relativistic
case for the typical plasma being responsible for the rotating neutron star. 相似文献
11.
The theory of the relaxation of pulsar angular velocity is compared with observational data for the first eight glitches of the Vela pulsar. Solutions of the inverse problem in relaxation theory are obtained in the regions of exponential and linear relaxation in the core of the neutron star. From these solutions, a distribution of vortices is found that results in the observed relaxation of the pulsar's angular velocity. It is shown that the pinning of neutron vortices plays the primary role in the region of exponential relaxation, while in the region of linear relaxation one must allow for the variation of the angular velocity of the superfluid component. 相似文献
12.
A. N. Timokhin 《Astrophysics and Space Science》2007,308(1-4):345-351
Pulsar “standard model”, that considers a pulsar as a rotating magnetized conducting sphere surrounded by plasma, is generalized
to the case of oscillating star. We developed an algorithm for calculation of the Goldreich-Julian charge density for this
case. We consider distortion of the accelerating zone in the polar cap of pulsar by neutron star oscillations. It is shown
that for oscillation modes with high harmonic numbers (l,m) changes in the Goldreich-Julian charge density caused by pulsations of neutron star could lead to significant altering of
an accelerating electric field in the polar cap of pulsar. In the moderately optimistic scenario, that assumes excitation
of the neutron star oscillations by glitches, it could be possible to detect altering of the pulsar radioemission due to modulation
of the accelerating field.
This work was partially supported by RFBR grant 04-02-16720, and by the grants N.Sh.-5218.2006.2 and RNP-2.1.1.5940. 相似文献
13.
Arun V. Thampan & Bhaskar Datta 《Monthly notices of the Royal Astronomical Society》1998,297(2):570-578
We calculate the disc and boundary layer luminosities for accreting rapidly rotating neutron stars with low magnetic fields in a fully general relativistic manner. Rotation increases the disc luminosity and decreases the boundary layer luminosity. A rapid rotation of the neutron star substantially modifies these quantities as compared with the static limit. For a neutron star rotating close to the centrifugal mass shed limit, the total luminosity has contribution only from the extended disc. For such maximal rotation rates, we find that well before the maximum stable gravitational mass configuration is reached, there exists a limiting central density, for which particles in the innermost stable orbit will be more tightly bound than those at the surface of the neutron star. We also calculate the angular velocity profiles of particles in Keplerian orbits around the rapidly rotating neutron star. The results are illustrated for a representative set of equation of state models of neutron star matter. 相似文献
14.
A class of well behaved charged superdense star models of embedding class one is obtained by taking perfect fluid to be interior
matter. In the process we come across the models for white dwarf, quark and neutron stars. Maximum mass of the star of this
class is found to be 6.716998M
Θ with its radius is 18.92112 Km. In the absence of charge the models reduce to Schwarzchild’s interior model with constant
density. 相似文献
15.
James B. Hartle 《Astrophysics and Space Science》1973,24(2):385-405
Equations are given which determine the moment of inertia of a rotating relativistic fluid star to second order in the angular
velocity with no other approximation being made. The equations also determine the moment of inertia of matter located between
surfaces of constant density in a rotationally distorted star; for example, the moments of inertia of the crust and core of
a rotationally distorted neutron star can be calculated in this way. The method is applied ton=3/2 relativistic polytropes and to neutron star models constructed from the Baym-Bethe-Pethick-Sutherland-Pandharipande equation
of state.
Supported in part by the National Science Foundation.
Alfred P. Sloan Research Fellow. 相似文献
16.
D. N. Sob’yanin 《Astronomy Letters》2016,42(11):745-751
The electromagnetic field in a magnetized neutron star and the underlying volume charges and currents are found. A general case of a rigidly rotating neutron star with infinite conductivity, arbitrary distribution of the internal magnetic field, arbitrarily changing angular velocity, and arbitrary surface velocity less than the velocity of light is considered. Quaternions are used to describe rotation and determine the magnetic field. It is shown that the charge density is not equal to and can exceed significantly the common Goldreich–Julian density. Moreover, corrections to the magnetic field due to stellar rotation are zero. For a rotating neutron star, twisting magnetic field lines causes charge accumulation and current flows. This fact shows a possible link between changing internal magnetic field topology and observed activity of neutron stars. 相似文献
17.
Yu. A. Rylov 《Astrophysics and Space Science》1985,117(1):5-34
The self-consistent balanced pulsar magnetosphere of a magnetic neutron star with aligned magnetic and rotational axes is considered. It is shown that the magnetosphere consists of electron polar caps separated by empty space from a positron equatorial belt. The shape of the cold polar caps at a large distance from the star is calculated. It is shown that the cap shape at a large distance is independent of the magnetospheric structure near the neutron star. The shape of the equatorial belt is calculated. It is shown that a part of the equatorial belt rotates differentially, and its angular velocity is larger than that of the star (superrotation). It is shown that under certain conditions the space charge density of the belt can be very large. In principle, the formation of a surface charge placed in vacuum on a magnetic surface is possible. Magnetospheric vibrations are considered. A connection is established between drifting subpulses and the equatorial belt superrotation and also between drifting subpulses and cap vibrations. The characteristic frequency of vibrations and the angular velocity of superrotation are estimated. 相似文献
18.
B. Kämpfer 《Astrophysics and Space Science》1983,93(1):185-197
The transition from a neutron star to a pion-condensed star is investigated in Newtonian hydrodynamics. It is shown that in
a certain range of ultradense equations of state, there occurs a mass ejection with energies comparable with usual supernova
outputs. But the ejected mass is only in the order of 0.02M
⊙.
Therefore, the observable consequences of this transition are not so dramatic as conjectured recently. In a realistic scenario
including a stiff ultradense equation of state and a weak effect of pion condensation the mass ejection disappears.
Additionally the collapse of a stellar core to a neutron star with pion-condensed core is considered. In comparison with a
standard supernova scenario we find only a slightly reduced explosion energy.
Further, the possible consequence of pion condensation during the secular evolution of the bounced core of a collapsing star
to the cool final neutron star is discussed. 相似文献
19.
Qi Zhan-qiang Ding Wen-bo Zhang Cheng-min Hou Jia-wei 《Chinese Astronomy and Astrophysics》2018,42(1):69-80
By the relativistic mean field theory and relevant weak-interactional cooling theory, the relativistic cooling properties in the conventional and hyperonic neutron star matter are studied. Also a comparison between the relativistic and non-relativistic results after taking consideration of the gravity correction is performed. The results show that the relativistic effect of neutrino emission reduces the neutrino emissivity, luminosity, and the cooling rate of stellar objects, in comparison with the non-relativistic case. In the neutron star matter without hyperon, the amplitude of the cooling rate reduction caused by the relativistic effect is maximal after taking the gravity correction into consideration, it attains 56% for a 2 M⊙ neutron star composed of conventional neutron star matter, and in the hyperonic matter the amplitude of reduction is minimal, about 38%. 相似文献
20.
Xian-Feng Zhao 《Astrophysics and Space Science》2011,332(1):139-144
The effect of the Σ-meson well depth on the gravitational redshift is examined within the framework of relativistic mean field
theory for the baryon octet system. It is found that, for a stable neutron star, the gravitational redshift increases with
the central energy density increase or with the mass increase but decreases as the radius increases. Considering a change
of US(N)U_{\Sigma}^{(N)} from −30 MeV to 30 MeV, for a stable neutron star the gravitational redshift near to the maximum mass increases. In addition,
it is also found that the growth of the US(N)U_{\Sigma}^{(N)} makes the gravitational redshift as a function of M
max /R increase, the higher the US(N)U_{\Sigma}^{(N)} the less the change in the gravitational redshift. 相似文献