Структура и эволюция Сверхмассивных вращающихся магнитных политроп

. - . . , . - . - , , , -. ., , .

---

The structure of rotating magnetic polytropes is considered in Roche approximation. Investigation of the influence of poloidal as well as toroidal magnetic fields on the conditions of the beginning of matter outflow due to rotational instability is carried out. The influence of the turbulent convection and twisting of magnetic force-lines on the time of smoothing of differential rotation is considered. The estimate of the magneto-turbulence energy generated by differential rotation is presented. Both maximum possible energy output and duration of the quasi-statical evolution phase up to the appearance of hydrodynamic instability due to the effects of general relativity are calculated for supermassive magnetic polytropes of index three with uniform or differential rotation. The radius-mass relation is obtained for supermassive differentially-rotating magnetic polytropes referring to the longest part of the quasi-statistical evolution stage; some consequences are pointed out, including the period-luminosity relation.The evolution of the considered models of supermassive rotating magnetic polytropes with different character of rotation and different geometry of a magnetic field is discussed.The results obtained are summarized in the last section.

---

---

English translation will appear in the next issue ofAstrophys. Space Sci.

---

Receipt delayed by postal strike in Great Britain     

Перенос резонансного излучения И случайные ълуждания Фотонов

. . .

---

Transfer of resonance radiation in infinite medium is considered as a process of random walks of photons. Close relation is shown to exist between the problems of transfer of line radiation and the stable distributions of the probability theory. This relation is used as a basis of a new method for the investigation of the asymptotic properties of the radiation field far from the sources.

---

---

,      

Profiles of the diffuse interstellar lines

The possibility that the diffuse interstellar lines and bands are but structure in the continuous extinction by dust grains is considered in detail. The lines are assumed to arise from impurities in the grains. Profiles of the strongest diffuse features are computed for a wide variety of host grain types and sizes, including size distributions of particles, and spheroidal and coated spherical grains.New observational profiles, of which 4430, 4765 and 4885 have been derived from automated spectrophotometry of electronographic spectra, are also presented; and comparison is made between theory and observation. The most useful tool of comparison is found to be the ratio of maximum apparent emission in the violet wing to maximum apparent absorption, . This ratio increases with size of the host particle, and with both real and imaginary parts of its refractive index; but is independent of the observed variations in strength and width of a particular line. The ratio is larger for 4430 than for the other lines.Taking into account current opinion as to the composition of interstellar dust, the observations may be explained by the presence of impurities in either silicate grains with effective radii of about 120 nm, or possibly graphite grains about 50 nm in radius coated with a thin dielectric condensate. None of the observed profiles are at variance with the hypothesis that all the lines arise from the same impurities in the same type of grains. The concentration of such impurities needed to reproduce the observed line profiles and strengths is only about one in 10⁴ atoms in the grain.     

The ellipsoidal variables IV: Light variations

The V variations of ellipsoidal variables are investigated as a function of the spectral type of the primary. A model is developed on the assumption that the primary has near Main-Sequence characteristics. It is argued that the observed minimum in the V variations around spectral type F is real and is due to variations in the gravity-darkening exponent . The absolute upper limit to V variations is found to be 0.2 mag.     

F07164+5301: an ESB source with WR features

We report on a new ESB source, as defined by Allenet al. (1991), with Wolf-Rayet (WR) bands in its optical spectrum. The WR bump at 4605-4686 is detected. The bump consists of broad HeII 4686, NV4605-4619, NIII4634-41, and possibly, CIII4647-52 emission. The narrow nebular lines are clearly discernable on our spectrum. The number of WR stars derived from the luminosity of HeII4686 is about 8100. The oxygen abundance is about 9.06×10^–4, greater than the solar value.     

Метагалактические протоны сверхвысоких энергий

, . 2.7°- . . . E3×10¹⁹ (1.6) .     

Рассеяние света на анизотропных частицах

, — . , , . , , .     

Взаимооействие Излучения Рентгеновскооо Истооника с АтмосФерой Нормальной Звезды в Тесных Двойных Системах

, . : , . , . . ( ) . . . HZ Her=Her X1, . . , . , ., hv 15–30 . , . Sco X1 .     

Ускорение релятивистских электронов в плазменных реакторах и нелинейные спектры космических радиоисточников

( , 1977; , 1977). , , , . .     

The loss-cone driven instability for Langmuir waves in an unmagnetized plasma

Analytic and numerical results are presented for the growth rate of Langmuir waves due to a loss-cone distribution of energetic electrons. The effect of the magnetic field on the wave-particle interaction is ignored, and the resonance condition is described in terms of a resonance hyperboloid in momentum space. The collisional evolution of a distribution of magnetically trapped electrons is followed numerically to show how a gap distribution develops. The growth is most favorable for an intermediate sized loss cone ( 45 °) and a gap distribution in which the mean energy of the suprathermal electrons is much larger than the thermal energy of the background electrons. It is plausible that loss-cone gap distributions do develop in the solar corona, and that they should lead to second harmonic plasma emission weakly polarized in the x-mode.     

The asymptotic limit of the form-factors α and β product for celestial bodies

The applicability of the properties of central configurations proceeding from the many-body problem to study of gaseous sphere cloud evolution during its gravitational contraction is justified. It is shown that the product runs to a constant value in the asymptotic time limit of simultaneous collision of all the particles of the cloud where is a form-factor of the potential energy and is a form-factor of the moment of inertia.The spherical bodies as well as ellipsoids of rotation and general ellipsoids with a one-dimensional mass distribution (k),k[0, 1] are found to possess the property =const.

---

. , - , , ., , - =const., , (k),k[0, 1].

     

Сопоставление модели карлсона с моделью сплошной среды

, (1962, 1963) . , (1) (2) .     

Некоторые асимптотические решения в ограниченной задаче трех тел

, . . . .

---

Some asymptotic solutions in the restricted problem of three bodies by L. G. Lukjanov.

Some particular solutions of the plane restricted problem of three bodies in the form of Liapunov's series are obtained. These solutions asymptotically approach the Lagrange solutions. Convergence is proved.

     

Околозвездные оБлака по данным 2800 Mgii

2800 Mgii (. 1). (N ⁺/N ₁1000) , , (N ⁺/N ₁10). , . —, , . — . : ; 0.002 1 , 0.1 ; () 100 ^–3; ; ; , 10 ; 10^–4 1 . 2800 Mgii .     

Формирование Универсальных и Диффузионных Участков Нелинйных Спектров Релятивистских Электронов В Пространственно Ограниченных Источниках

, () , , ( =2) , . (, , ). ( =0,5) .     

Возможный механизм радиоизлучения пульсаров

, , , , , . , , . - . — , , .     

Material ejecta in a disturbed solar filament

H observations, using the Multichannel Subtractive Double Pass (MSDP) spectrograph operating on the Meudon Solar Tower, have been made of an active region filament which undergoes a disparition brusque. The period of observation was from 10 45 to 13 30 UT on 22 June, 1981. Velocity and intensity fluctuations in H were measured. The proper motions of ejecta were followed allowing their trajectories and vector velocities to be determined. To model the dynamics of ejecta several models using thermal or magnetic driving forces are compared. The most promising model explains the motion as the consequence of magnetic stresses acting on an isolated magnetized plasmoïd in a diverging flux tube.     

Constraints on the high-energy properties of active galactic nuclei

Number-flux relations at -ray energies for active galactic nuclei have been computed, starting from their X-ray luminosity function and making different assumptions on the spectral shape and cosmological evolution of these sources.The radiation resulting from their integrated emission has been computed and compared to the observed intensity and spectrum of the extragalactic -ray diffuse background (0.3–20 MeV), in order to derive quantitative constraints on the evolution and spectral properties of active galactic nuclei at -ray energies.Paper presented at the 11th European Regional Astronomical Meetings of the IAU on New Windows to the Universe, held 3–8 July, 1989, Tenerife, Canary Islands, Spain.     

ОJ 287: Поляризационное и фотометрическое поведение В 1971–1976 гг

J 287 1972–1976. , . . J ( ), () . (₀=80°) . J 287 ¶ . p=42.8%, ₀=101°. (50%).     

турбулентноштб в космологии

=qr, I II (Marochniket al., 1975 a, b), . , II; , . , , ye , . . t _g.