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Том 61, № 7 (2017)
- Год: 2017
- Статей: 6
- URL: https://journals.rcsi.science/1063-7729/issue/view/11975
Article
Galactic orbits of globular clusters in the region of the Galactic bulge
Аннотация
Galactic orbits have been constructed over long time intervals for ten globular clusters located near the Galactic center. A model with an axially symmetric gravitational potential for the Galaxy was initially applied, after which a non-axially symmetric potential corresponding to the central bar was added. Variations in the trajectories of all these globular clusters in the XY plane due to the influence of the bar were detected. These were greatest for the cluster Terzan 4 in the meridional (RZ) plane. The globular clusters Terzan 1, Terzan 2, Terzan 4, Terzan 9, NGC 6522, and NGC 6558 always remained within the Galactic bulge, no farther than 4 kpc from the Galactic center.
551-559
Features of the accretion in the EX Hydrae system: Results of numerical simulation
Аннотация
A two-dimensional numerical model in the axisymmetric approximation that describes the flow structure in the magnetosphere of the white dwarf in the EX Hya system has been developed. Results of simulations show that the accretion in EX Hya proceeds via accretion columns, which are not closed and have curtain-like shapes. The thickness of the accretion curtains depends only weakly on the thickness of the accretion disk. This thickness developed in the simulations does not agree with observations. It is concluded that the main reason for the formation of thick accretion curtains in the model is the assumption that the magnetic field penetrates fully into the plasma of the disk. An analysis based on simple estimates shows that a diamagnetic disk that fully or partially shields the magnetic field of the star may be a more attractive explanation for the observed features of the accretion in EX Hya.
560-572
Stars with relativistic speeds in the Hills scenario
Аннотация
The dynamical capture of a binary system consisting of a supermassive black hole (SMBH) and an ordinary star in the gravitational field of a central (more massive) SMBH is considered in the three-body problem in the framework of a modified Hills scenario. The results of numerical simulations predict the existence of objects whose spatial speeds are comparable to the speed of light. The conditions for and constraints imposed on the ejection speeds realized in a classical scenario and the modified Hills scenario are analyzed. The star is modeled using an N-body approach, making it possible to treat it as a structured object, enabling estimation of the probability that the object survives when it is ejected with relativistic speed as a function of the mass of the star, the masses of both SMBHs, and the pericenter distance. It is possible that the modern kinematic classification for stars with anomalously high spatial velocities will be augmented with a new class—stars with relativistic speeds.
573-590
Magnetic fields of radio pulsars
Аннотация
The mechanism of magnetodipole braking of radio pulsars is used to calculate new values of the surface magnetic fields of neutron stars. The angles β between the spin axes and magnetic moments of the neutron stars were estimated for 376 radio pulsars using three different methods. It is shown that small inclinations of magnetic axes dominate. The equatorial magnetic fields for the considered sample of pulsars are calculated using the β values obtained. As a rule, these magnetic fields are a factor of a few higher than the corresponding values in known catalogs.
591-611
The probable quadruple systems FK Aql and FZ Del
Аннотация
Orbital-period variations of the eclipsing binaries FK Aql and FZ Del are analyzed. For each of the systems, a superposition of two cyclic variations of their orbital periods is found. FK Aql may be a quadruple system that contains two more bodies, besides the eclipsing binary, with masses M3 ⩾ 1.75M⊙ and M4 ⩾ 1.47M⊙, and the corresponding periods 15 and 82 yrs. This could also be a triple system with a third body of mass M3 ⩾ 1.75M⊙ and a period of the long-period orbit P3 = 15 yrs, or with a third body of mass M3 ⩾ 1.30M⊙ and a period of the long-period orbit P3 = 82 yrs. FZ Del may be a quadruple system with the additional componentmasses M3 ⩾ 0.2M⊙ and M4 ⩾ 0.3M⊙, with the periods 10.2 and 53.7 yrs. This could also be a triple system with a third-body mass M3 ⩾ 0.2M⊙ and a period of the long-period orbit P3 = 10.2 yrs. In both systems, the residual period variations could be due to magnetic cycles of the secondary. The period variations of the eclipsing binary FZ Del could also be due to apsidal motion, together with the influence of a third body or the effects of magnetic activity.
612-623
The resolvent relation of Sobolev for vector integral transfer equations in a half-space
Аннотация
The semi-inverse factorization method for the derivation of the Sobolev resolvent relation (SRR) for the transfer of radiation in a homogeneous half-space is proposed. The SRR is extended to vector, integral transfer equations. The method is compared with the non-linear factorization equation method. The application of the SRR to the transfer of resonance radiation is discussed.
624-630