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Astronomy Letters - The birth function of neutron stars in magnetic field $$B$$ is estimated for two models of the evolution of radio pulsars corresponding to different directions of evolution of... 相似文献
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V. A. Dogiel A. V. Gurevich Ya. N. Istomin K. P. Zybin 《Astrophysics and Space Science》2005,297(1-4):201-211
Acceleration of charged particles by neutral gas turbulence in giant molecular clouds is considered. The gamma-ray emission
from these clouds is estimated. It is shown that molecular clouds can be the counterparts of some of unidentified sources. 相似文献
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A.E. Kontorovich A.N. Fomin V.O. Krasavchikov A.V. Istomin 《Russian Geology and Geophysics》2009,50(11):917-929
Thermal maturation for the top and base of the Jurassic in the West Siberian megabasin was modeled on the basis of the vitrinite reflectance (Rvt0) data using mathematical modeling and computer simulations. The values of thermal maturation are found to vary within substages PC3-MC32 for the top (or being equivalent to PC3-MC12 on the periphery and southern part of the basin, or to MC2-MC32 in the north) and PC3-AC3 for the base of the Jurassic (or being equivalent to PC3-MC2 on the periphery and southern part of the basin or MC31-AC3 in the north). Thermal maturity levels of the Jurassic in West Siberia are controlled by depths of burial and peak temperatures which the source rocks were subjected to during this period. The situation is further complicated by high heat flows superimposed on the regional background, which are observed in deep fault zones and in the proximity of numerous igneous bodies. 相似文献
5.
Ya. N. Istomin 《Astronomy Reports》2005,49(6):446-449
The close neutron-star binary system comprised of the radio pulsars PSR J0737-3039 A,B is discussed. An analysis of the observational data indicates that the wind from pulsar A, which is more powerful than the wind from pulsar B, strongly distorts the magnetosphere of pulsar B. A shock separating the relativistic wind from pulsar A and the corotating magnetosphere of pulsar B should form inside the light cylinder of pulsar B. A weakly diverging “tail” of magnetic field is also formed, which stores a magnetic energy on the order of 1030 erg. This energy could be liberated over a short time on the order of 0.1 s as a result of reconnection of the magnetic-force lines in this “tail,” leading to an outburst of electromagnetic radiation with energies near 100 keV, with an observed flux at the Earth of 4 × 10?11 erg cm?2 s?2. Such outbursts would occur sporadically, as in the case of magnetic substorms in the Earth’s magnetosphere. 相似文献
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A. D. Kuz’min Ya. N. Istomin B. Ya. Losovskiȝ S. V. Logvinenko D. V. Dumskiȝ 《Astronomy Reports》2010,54(5):433-436
The frequency dependence of scattering of the radio emission from the Crab pulsar at the low frequencies 111, 63, and 44 MHz
has been measured and analyzed during sporadic enhancements of scattering and dispersion measure in October–December 2006
and December 2008. The frequency dependence of the scattering differs from the generally accepted dependence, τ
sc
(ν) ∝ ν
γ
, where γ = −4.0 for Gaussian and γ = −4.4 for power-law Kolmogorov distributions of inhomogeneities of the scattering medium. In intervals of enhancement, the
exponent of the frequency dependence γ decreased to −3.2(0.2) at the above frequencies. A model is proposed in which this is due to the presence of a dense plasma
structure in the nebula in the line of sight toward the pulsar, in which scattering of the radio emission on turbulence differs
from scattering in the interstellar medium. It is shown that the frequency dependence of scattering of the radio emission
can be weaker in a dense plasma than in the rarefied interstellar medium. 相似文献
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Dunite samples from a borehole drilled in the platiniferous concentrically-zoned Kondyor Massif are studied by electron spin
resonance (ESR). The spectrum profiles, relative intensities I, and volume magnetic susceptibilities κ are analyzed. These values experience strong irregular variations, sometimes by an
order of magnitude, in the upper and medium parts of the column, at depths from 100 to 400 m; and the variations decay at
greater depths. The magnetic properties of the samples are determined by iron (II) ions in the olivine lattice and by iron
(III) ions in the magnetite and pyrrhotite microphases and in the products of breakdown of the solid solution: chromiferous
magnetite, chromoferrite, etc. The I and κ values are directly related: κmax = 27.8 × 10−3 SI units, κmin=2.63 × 10−3 SI units, and κmean = 12.7 × 10−3 SI units. The maximum κ values are found in the zones with elevated contents of magnetite and pyrrhotite particles, and the
minimum ones, in zones with few medium and small clusters with Fe3+ ions. The uneven distributions of solid solutions and magnetic phases over depths are suggested to be related to the disturbances
in the conditions of crystallization. 相似文献
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A consistent theory of excitation, stabilization, and propagation of electromagnetic oscillations in a relativistic one-dimensional electron-positron plasma flowing along curved magnetic field lines is presented. It is shown that in such a medium which is typical of the magnetosphere of a neutron star there exist unstable natural modes of oscillations. Nonlinear saturation of the instability leads to an effective energy conversion into transverse oscillations capable of leaving the magnetosphere of a pulsar. The polarization spectrum and the directivity pattern of generated radiation are determined. A comparison with observations has shown that the theory makes it possible to explain practically all the basic characteristics of observed pulsar radio emission. 相似文献
10.
The motion of electrons and positrons in the vacuum magnetosphere of a neutron star with a surface magnetic field of B ≈ 1012 G is considered. Particles created in the magnetosphere or falling into it from outside are virtually instantaneously accelerated to Lorentz factors γ ≈ 108. After crossing the force-free surface, where the projection of the electric field onto the magnetic field vanishes, a particle begins to undergo ultra-relativistic oscillations. The particle experiences a regular drift along the force-free surface simultaneous with this oscillatory motion. 相似文献