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1.
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
2.
Equations for the dynamics of a rotating two-component neutron star are derived in the framework of the general theory of
relativity. The density of neutron vortex filaments is expressed in terms of the angular momentum density of the superfluid
neutrons in the “npe” phase of the neutron star. It is shown that a theory of the relaxation of the angular velocity of pulsars
must include corrections associated with the deviation of g00 from unity, which is a consequence of the curvature of space. 相似文献
3.
The superfluid core (“npe” phase) of a neutron star, consisting of superfluid neutrons, superconducting protons, and normal
electrons, is considered. The Gibbs thermodynamic potential of a superconducting proton vortex in a proton superconductor
of the second kind, interacting with the normal core of a neutron vortex of radius r ≪ λ parallel to it (λ is the depth of
penetration), is calculated. It is shown that under this assumption, the capture by the core of only one vortex turns out
to be energetically favored. The force exerted on the proton vortex by the entrainment current, always directed toward the
core, is found. The corresponding force for a proton antivortex is directed outward toward the outer boundary of the neutron
vortex. It is shown that the fluctuational formation of a vortex-antivortex pair is possible at a large distance from the
core under the action of the entrainment current. Under the action of the entrainment current, the antivortex travels outward,
while the vortex remains inside the neutron vortex. It is shown that the formation of new proton vortices is possible only
in the region in which the entrainment magnetic field strength is H(ρ) > Hcl (Hcl is the first critical field).
Translated from Astrofizika, Vol. 42, No. 2, pp. 225–234, April–June, 1999 相似文献
4.
The dynamics of the vortex lattice in the inner crust of a neutron star is considered. A general equation of motion is obtained
and solved under the assumption that there are regions of pinned and of free vortices. By comparing these solutions with observational
data for the Vela pulsar, the relative moments of inertia of regions of relaxation with the corresponding characteristic times
are calculated for two model stars with different equations of state. It is shown that the theory can be reconciled with observations
of the relaxation of pulsar angular velocity only for model stars with extremely stiff equations of state.
Translated from Astrofizika, Vol. 40, No. 1, pp. 67–76, January–March, 1997. 相似文献
5.
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
6.
The nonstationary dynamics of vortices in conventional type II superconductors and in neutron stars is examined in the Newtonian
approximation. A relaxation equation is obtained for vortices approaching an equilibrium distribution after a change in an
external magnetic field. The relaxation times are estimated for vortices in low-temperature superconductors and for proton
vortices in the superconducting core of a neutron star. It is shown that the proton vortex system created by entrainment currents
is rigidly coupled to the neutron vortices.
Translated from Astrofizika, Vol. 52, No. 2, pp. 291–300 (May 2009). 相似文献
7.
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
8.
The dynamics of the rotating two-component system in the core of a neutron star is considered. Equations of motion are derived with allowance for the pinning and depinning of neutron vortices, and general solutions of these equations are found for relatively small changes in the star's angular velocity. It is shown that these solutions can describe both a jump in a pulsar's angular velocity and its subsequent relaxation. The characteristic pinning and depinning times are estimated qualitatively from observational data for jumps in the angular velocity of the Vela pulsar.Translated from Astrofizika, Vol. 39, No. 4, pp. 593–604, October–December, 1996. 相似文献
9.
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
10.
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
11.
The forces acting on the solid crust of a differentially rotating neutron star are examined when a nonuniform excess of chemical
potential exists. The resultant of the external forces, a stress force, is expressed in terms of a centrifugal buoyancy force
and the deformation of the star’s crust under the action of this force is calculated. It is shown that there is a region within
the star where the resulting stresses lead to fracture of the crust when the difference in the angular velocities of the superfluid
and normal components reaches a critical value. The “centrifugal buoyancy” mechanism for generating a glitch is used to estimate
the parameters of glitches in the Vela pulsar.
__________
Translated from Astrofizika, Vol. 50, No. 2, pp. 183–197 (May 2007). 相似文献
12.
Pranab Ghosh 《Journal of Astrophysics and Astronomy》1995,16(2):289-305
I review our understanding of the evolution of the spin periods of neutron stars in binary stellar systems, from their birth
as fast, spin-powered pulsars, through their middle life as accretion-powered pulsars, upto their recycling or “rebirth” as
spin-powered pulsars with relatively low magnetic fields and fast rotation. I discuss how the new-born neutron star is spun
down by electromagnetic and “propeller” torques, until accretion of matter from the companion star begins, and the neutron
star becomes an accretion-powered X-ray pulsar. Detailed observations of massive radio pulsar binaries like PSR 1259-63 will
yield valuable information about this phase of initial spindown. I indicate how the spin of the neutron star then evolves
under accretion torques during the subsequent phase as an accretion-powered pulsar. Finally, I describe how the neutron star
is spun up to short periods again during the subsequent phase of recycling, with the accompanying reduction in the stellar
magnetic field, the origins of which are still not completely understood. 相似文献
13.
A theory of the relaxation of pulsar angular velocity is compared with observational data for the first eight glitches of the Vela pulsar. The inverse problem of the theory of relaxation is considered and solutions of this problem in the regions of exponential and linear relaxation are found. General features in the distribution of neutron vortices in these regions immediately after a glitch are determined. It is shown that these properties may be related to the size of the glitch in pulsar angular velocity. 相似文献
14.
The gravitational rotation of slowly rotating neutron stars with rough surfaces is examined. The source of the gravitational
waves is assumed to be the energy transferred to the crust of the star during irregular changes in its angular rotation velocity.
It is shown that individual pulsars whose angular velocity regularly undergoes glitches will radiate a periodic gravitational
signal that can be distinguished from noise by the latest generation of detectors. Simultaneous recording of a gravitational
signal and of a glitch in the angular velocity of a pulsar will ensure reliable detection of gravitational radiation.
__________
Translated from Astrofizika, Vol. 49, No. 2, pp. 221–229 (May 2006). 相似文献
15.
Armen Sedrakian James M. Cordes 《Monthly notices of the Royal Astronomical Society》1999,307(2):365-375
We show that the crust–core interface in neutron stars acts as a potential barrier to the peripheral neutron vortices approaching the interface in the model in which these are coupled to the proton vortex clusters. This elementary barrier arises because of the interaction of vortex magnetic flux with the Meissner currents set up by the crustal magnetic field at the interface. The dominant part of the force is derived from the cluster–interface interaction. As a result of the stopping of the continuous neutron vortex current through the interface, angular momentum is stored in the superfluid layers in the vicinity of the crust–core interface during the interglitch period. Discontinuous annihilation of proton vortices at the boundary restores the neutron vortex current and spins up the observable crust on short time-scales, leading to a glitch in the spin characteristics of a pulsar. 相似文献
16.
M. Ali Alpar 《Journal of Astrophysics and Astronomy》2017,38(3):44
G. Srinivasan et al. (1990) proposed a simple and elegant explanation for the reduction of the neutron star magnetic dipole moment during binary evolution leading to low mass X-ray binaries and eventually to millisecond pulsars: Quantized vortex lines in the neutron star core superfluid will pin against the quantized flux lines of the proton superconductor. As the neutron star spins down in the wind accretion phase of binary evolution, outward motion of vortex lines will reduce the dipole magnetic moment in proportion to the rotation rate. The presence of a toroidal array of flux lines makes this mechanism inevitable and independent of the angle between the rotation and magnetic axes. The incompressibility of the flux-line array (Abrikosov lattice) determines the epoch when the mechanism will be effective throughout the neutron star. Flux vortex pinning will not be effective during the initial young radio pulsar phase. It will, however, be effective and reduce the dipole moment in proportion with the rotation rate during the epoch of spindown by wind accretion as proposed by Srinivasan et al. The mechanism operates also in the presence of vortex creep. 相似文献
17.
M. G. Abrahamyan 《Astrophysics》2009,52(1):119-131
The nonlinear dynamics of a rotating jet is examined following its ejection from a compact gravitating object by a vortex
mechanism. A scenario is described in which a dense stream expands and is subsequently transformed into a nonstationary vortex
consisting of a cylindrical core and a “sheath.” At this stage of development, a converging radial flow of matter in the differentially
rotating nonuniform sheath collimates the jet and speeds up the rotation of the core, as well as the flow of matter along
the jet, in accordance with a power law or “explosive” instability, until the velocity discontinuity at the surface of the
core approaches the sound speed. Flows of this type have low energy dissipation and can serve as unique channels for the acceleration
and collimation of jet eruptions from young stars, active galactic nuclei, and quasars.
Translated from Astrofizika, Vol. 52, No. 1, pp. 135–145 (February 2009). 相似文献
18.
If cooled-down neutron stars have a thin atomic crystalline–iron crust, they must diffract X-rays of appropriate wavelength.
If the diffracted beam is to be visible from Earth (an extremely rare but possible situation), the illuminating source must
be very intense and near the reflecting star. An example is a binary system composed of two neutron stars in close orbit,
one of them inert, the other an X-ray pulsar. (Perhaps an “anomalous” X-ray pulsar or magnetar, not powered by gas absorption
from the companion or surrounding space, would be the cleanest example.) The observable to be searched for is a secondary
peak added (quasi-) periodically to the main X-ray pulse. The distinguishing feature of this secondary peak is that it appears
at wavelengths related by simple integer numbers, λ,λ/2,λ/3,…,λ/n because of Bragg’s diffraction law. 相似文献
19.
In the method of variation of parameters we express the Cartesian coordinates or the Euler angles as functions of the time
and six constants. If, under disturbance, we endow the “constants” with time dependence, the perturbed orbital or angular
velocity will consist of a partial time derivative and a convective term that includes time derivatives of the “constants”.
The Lagrange constraint, often imposed for convenience, nullifies the convective term and thereby guarantees that the functional
dependence of the velocity on the time and “constants” stays unaltered under disturbance. “Constants” satisfying this constraint
are called osculating elements. Otherwise, they are simply termed orbital or rotational elements. When the equations for the
elements are required to be canonical, it is normally the Delaunay variables that are chosen to be the orbital elements, and
it is the Andoyer variables that are typically chosen to play the role of rotational elements. (Since some of the Andoyer
elements are time-dependent even in the unperturbed setting, the role of “constants” is actually played by their initial values.)
The Delaunay and Andoyer sets of variables share a subtle peculiarity: under certain circumstances the standard equations
render the elements nonosculating. In the theory of orbits, the planetary equations yield nonosculating elements when perturbations
depend on velocities. To keep the elements osculating, the equations must be amended with extra terms that are not parts of the disturbing function [Efroimsky, M., Goldreich, P.: J. Math. Phys. 44, 5958–5977 (2003); Astron. Astrophys. 415, 1187–1199 (2004); Efroimsky, M.: Celest. Mech. Dyn. Astron. 91, 75–108 (2005); Ann. New York Acad. Sci. 1065, 346–374 (2006)]. It complicates both the Lagrange- and Delaunay-type planetary equations and makes the Delaunay equations
noncanonical. In attitude dynamics, whenever a perturbation depends upon the angular velocity (like a switch to a noninertial
frame), a mere amendment of the Hamiltonian makes the equations yield nonosculating Andoyer elements. To make them osculating,
extra terms should be added to the equations (but then the equations will no longer be canonical). Calculations in nonosculating
variables are mathematically valid, but their physical interpretation is not easy. Nonosculating orbital elements parameterise
instantaneous conics not tangent to the orbit. (A nonosculating i may differ much from the real inclination of the orbit, given by the osculating i.) Nonosculating Andoyer elements correctly describe perturbed attitude, but their interconnection with the angular velocity
is a nontrivial issue. The Kinoshita–Souchay theory tacitly employs nonosculating Andoyer elements. For this reason, even
though the elements are introduced in a precessing frame, they nevertheless return the inertial velocity, not the velocity
relative to the precessing frame. To amend the Kinoshita–Souchay theory, we derive the precessing-frame-related directional
angles of the angular velocity relative to the precessing frame. The loss of osculation should not necessarily be considered
a flaw of the Kinoshita–Souchay theory, because in some situations it is the inertial, not the relative, angular velocity
that is measurable [Schreiber, K. U. et al.: J. Geophys. Res. 109, B06405 (2004); Petrov, L.: Astron. Astrophys. 467, 359–369 (2007)]. Under these circumstances, the Kinoshita–Souchay formulae for the angular velocity should be employed (as
long as they are rightly identified as the formulae for the inertial angular velocity). 相似文献
20.
P. B. Jones 《Monthly notices of the Royal Astronomical Society》2009,397(2):1027-1031
The quantum phenomenon of spectral flow which has been observed in laboratory superfluids, such as 3 He-B, controls the drift velocity of proton type II superconductor vortices in the liquid core of a neutron star and so determines the rate at which magnetic flux can be expelled from the core to the crust. In the earliest and most active phases of the anomalous X-ray pulsars and soft-gamma repeaters, the rates are low and consistent with a large fraction of the active crustal flux not linking the core. If normal neutrons are present in an appreciable core matter-density interval, the spectral flow force limits flux expulsion in cases of rapid spin-down, such as in the Crab pulsar or in the propeller phase of binary systems. 相似文献