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1.
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
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 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
4.
The Ginzburg-Landau equations are derived for the magnetic and gluomagnetic gauge fields of nonabelian semi-superfluid vortex
filaments in color superconducting cores of neutron stars containing a diquark CFL condensate. The interaction of the diquark
CFL condensate with the magnetic and gluomagnetic gauge fields is taken into account. The asymptotic values of the energies
of these filaments are determined from the quantization conditions. It is shown that a lattice of semi-superfluid vortex filaments
with a minimal quantum of circulation develops in the quark superconducting core during rotation of the star. The magnetic
field in the core of this vortex is on the order of 1018 G. A cluster of proton vortices, which develops in the hadron phase surrounding every superfluid neutron vortex owing to
an entrainment effect, creates new semi-superfluid vortex filaments with a minimal quantum of circulation in the quark superconducting
core.
Translated from Astrofizika, Vol. 51, No. 4, pp. 633–646 (November 2008). 相似文献
5.
Fluctuational mechanism for the formation of proton vortices in the superfluid core of neutron stars
The Gibbs thermodynamic potential of a proton vortex interacting with the normal core of a neutron vortex of radius r << λ (λ is the penetration depth) that is parallel to it and has an outer boundary of radius b is calculated. It is shown that, under
this assumption, the capture of only one vortex by the core is energetically favorable. The force acting on the proton vortex
owing to the entrained current is found and it is always directed toward the core. The corresponding force for a proton antivortex
is directed toward the outer boundary of the neutron vortex. The Ginzburg-Landau equation is solved for a vortex-antivortex
system and its Gibbs function is calculated. It is shown that at large distances from the core, vortex-antivortex pairs can
form because of fluctuations. Acted on by the entrainment current, the antivortex moves outward, while the vortex stays inside
the neutron vortex. It is shown that the best conditions for fluctuational pair production, followed by separation, exist
near the outer boundary. It is shown that new proton vortices can develop only in a region where the entrainment magnetic
field strength H (ρ) > HC1 (HC1 is the lower critical field).
__________
Translated from Astrofizika, Vol. 51, No. 1, pp. 139–149 (February 2008). 相似文献
6.
The Ginzburg-Landau equations are derived for the magnetic and gluomagnetic gauge fields in the color superconducting core
of a neutron star containing a CFL-condensate of diquarks. The interaction of the diquark CFL-condensate with the magnetic
and gluomagnetic gauge fields is taken into account. The behavior of the magnetic field in a neutron star is studied by solving
the Ginzburg-Landau equations taking correct account of the boundary conditions, including the gluon confinement conditions.
The magnetic field distribution in the quark and hadronic phases of a neutron star is found. It is shown that a magnetic field
generated in the hadronic phase by the entrainment effect penetrates into the quark core in the form of quark vortex filaments
because of the presence of screening Meissner currents.
__________
Translated from Astrofizika, Vol. 50, No. 1, pp. 87–98 (February 2007). 相似文献
7.
The effect of proton superconductivity on the generation of a toroidal magnetic field inside a neutron star is examined. It
is shown that including the entrainment of superconducting protons by superfluid neutrons does not change the previously obtained
results. Proton superconductivity does influence the structure of the generated magnetic field since, over a time on the order
of 104–105 years, the magnetic field increases linearly with time and can exceed the first critical field for proton superconductivity.
The distribution of the stationary toroidal magnetic field inside a neutron star is also found. 相似文献
8.
M. K. Shahabasyan 《Astrophysics》2009,52(1):151-155
Collective elastic oscillations of a lattice of nonabelian quark semisuperfluid vortex filaments in the superfluid core of
a rotating neutron star are examined. It is shown that in the incompressible fluid approximation, transverse long wavelength
oscillations (Tkachenko oscillations) owing to shear deformation of the vortex lattice propagate in a plane perpendicular
to the axis of rotation. The periods of these oscillations are consistent with rotational variations on the order of 100-1000 days
observed in the pulsars PSR B0531+21 and PSR B1828-11.
Translated from Astrofizika, Vol. 52, No. 1, pp. 165–169 (February 2009). 相似文献
9.
D. M. Sedrakian 《Astrophysics》2000,43(3):275-281
The influence of the effect of entrainment of superconducting protons by superfluid neutrons on the distribution of neutron
vortices in a rotating neutron star is investigated. It is shown that the proton vortex clusters generated by entrainment
currents create the magnetic structure of a neutron vortex. The average magnetic field induction in a neutron vortex is calculated.
The presence of the magnetic field of a neutron vortex considerably alters the radius of the vortex zone. The width of the
vortex-free zone at the surface of the neutron star’s core increases, reaching macroscopic values on the order of several
meters. This result considerably changes earlier concepts of the distribution of neutron vortices in a neutron star.
Translated from Astrofizika, Vol. 43, No. 3, pp. 377-386, July–September, 2000. 相似文献
10.
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
11.
The magnetic field distribution in the superfluid, spherical, hadronic core of a rotating neutron star, which consists of vortex and vortex-free zones, is investigated. Due to the effect of entrainment of superconducting protons by rotating superfluid neutrons, a nonuniform magnetic field, the average value of which is constant, is formed in the vortex zone of the neutron star, directed parallel to the star's axis of rotation. It is shown that at the stellar surface, near the equatorial plane, there is a vortex-free zone of macroscopic size in which there is no magnetic field. The magnetic field near the boundaries of the vortex-free zone falls off exponentially with depth into the interior of this zone. This result essentially alters earlier concepts about the magnetic field distribution in the superfluid hadronic core of a neutron star. Outside the hadronic core the magnetic field has a dipole character with a magnetic moment on the order of 1030 g×cm3. 相似文献
12.
In 1968–2005 different observers (mainly, one of the authors—V.M. Lyuty) performed numerous measurements of luminosity of
the nucleus of the Seyfert galaxy NGC 4151. It is shown that (a) luminosity of the object pulsated over 38 years with a period of 160.0106(7) min coinciding, within the error limits, with
the well-known period P
0 = 160.0101(2) min of the enigmatic “solar” pulsations, and (b) when registering oscillations of luminosity of NGC 4151 nucleus with the P
0 period, time moments of observations must be reduced to the earth instead of the sun, i.e., to the reference frame of the
observer. The coherent P
0 oscillation is characterized, therefore, by invariability of both frequency and phase with respect to redshift z and the earth’s orbital motion, respectively. From these results it, thus, follows that the coherent P
0 oscillation seems to be of a true cosmological origin. The P
0 period itself might represent a course of the “cosmic clock” related to the existence of an absolute time of the Universe
in Newton’s comprehension. 相似文献
13.
B. Haskell 《Astrophysics and Space Science》2007,308(1-4):541-543
The aim of this work is to compare a neutron star with an accreted crust and one with a non-accreted crust, and estimate which
one is potentially a better source of gravitational waves (i.e. can sustain a larger “mountain”). To do this we present a
new formalism, and find that a non-accreted crust can sustain a slightly larger “mountain”. We also discuss the importance
of relativistic effects.
相似文献
14.
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
15.
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
16.
N. R. Ikhsanov 《Astrophysics and Space Science》2007,308(1-4):137-140
Accretion of interstellar material by an isolated neutron star is discussed. The point I address here is the interaction between
the accretion flow and the stellar magnetosphere. I show that the interchange instabilities of the magnetospheric boundary
under the conditions of interest are basically suppressed. The entry of the material into the magnetosphere is governed by
diffusion. Due to this reason the persistent accretion luminosity of isolated neutron stars is limited to <4×1026 erg s−1. These objects can also appear as X-ray bursters with the burst durations of ∼30 min and repetition time of ∼105 yr. This indicates that the number of the accreting isolated neutron stars which could be observed with recent and modern
X-ray missions is a few orders of magnitude smaller than that previously estimated.
相似文献
17.
Z. F. Gao N. Wang J. P. Yuan L. Jiang D. L. Song E. L. Qiao 《Astrophysics and Space Science》2011,333(2):427-435
In this paper, we consider the effect of Landau levels on the decay of superhigh magnetic fields of magnetars. Applying 3
P
2 anisotropic neutron superfluid theory yield a second-order differential equation for a superhigh magnetic field B and its evolutionary timescale t. The superhigh magnetic fields may evolve on timescales ∼(106–107) yrs for common magnetars. According to our model, the activity of a magnetar may originate from instability caused by the
high electron Fermi energy. 相似文献
18.
We investigate the combined effect of neutron and proton superfluidities on the cooling of neutron stars whose cores consist of nucleons and electrons. We consider the singlet state paring of protons and the triplet pairing of neutrons in the cores of neutron stars. The critical superfluid temperatures T c are assumed to depend on the matter density. We study two types of neutron pairing with different components of the total angular momentum of a Cooper pair along the quantization axis (|m J |=0 or 2). Our calculations are compared with the observations of thermal emission from isolated neutron stars. We show that the observations can be interpreted by using two classes of superfluidity models: (1) strong proton superfluidity with a maximum critical temperature in the stellar core T c max ?4×109 K and weak neutron superfluidity of any type (T c max ?2×108 K); (2) strong neutron superfluidity (pairing with m J =0) and weak proton superfluidity. The two types of models reflect an approximate symmetry with respect to an interchange of the critical neutron and proton pairing temperatures. 相似文献
19.
G. B. Alaverdyan 《Astrophysics》2009,52(1):132-150
The equation of state of neutron star matter is examined in terms of the relativistic mean-field theory, including a scalar-isovector
δ-meson effective field. The constants of the theory are determined numerically so that the empirically known characteristics
of symmetric nuclear matter are reproduced at the saturation density. The thermodynamic characteristics of both asymmetric
nucleonic matter and β-equilibrium hadron-electron npe-plasmas are studied. Assuming that the transition to strange quark
matter is an ordinary first-order phase transition described by Maxwell's rule, a detailed study is made of the variations
in the parameters of the phase transition owing to the presence of a δ-meson field. The quark phase is described using an
improved version of the bag model, in which interactions between quarks are accounted for in a one-gluon exchange approximation.
The characteristics of the phase transition are determined for various values of the bag parameter within the range B ∈ [60,120]MeV/fm3 and it is shown that including a δ-meson field leads to a reduction in the phase transition pressure P
0 and in the concentrations n
N
and n
Q
at the phase transition point.
Translated from Astrofizika, Vol. 52, No. 1, pp. 147–164 (February 2009). 相似文献
20.
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