A model of interplanetary and coronal magnetic fields

A model of the large-scale magnetic field structure above the photosphere uses a Green's function solution to Maxwell's equations. Sources for the magnetic field are related to the observed photospheric field and to the field computed at a source surface about 0.6 R above the photosphere. The large-scale interplanetary magnetic field sector pattern is related to the field pattern at this source surface. The model generates magnetic field patterns on the source surface that compare well with interplanetary observations. Comparisons are shown with observations of the interplanetary magnetic field obtained by the IMP-3 satellite.     

The activity of stellar aggregates and the origin of cosmic rays

A concept of stellar aggregate activity is advanced. It is shown that the aggregate activity is too high in order to generate cosmic rays. Two conditions lay claim to cosmic ray primary sources: (i) a very large number of sources (10⁴), and (ii) a homogeneous distribution of sources in the Galaxy. Supernovae do not satisfy both those conditions, but stellar aggregates do. The total interstellar medium of the aggregate identifies with a supernova remnant and possesses properties favourable for the acceleration of cosmic rays up to a high energy by statistical mechanisms. The direct suppliers of primary cosmic rays are the flare stars in the aggregates. From the point of view of energetic resources as well as the energetic consistency of cosmic rays, aggregates are equivalent with supernova remmants. The aggregate must also be the source of gamma-rays. The usual UV Cet-type flare stars in the Sun's neighbourhood do not play any role as sources of primary cosmic rays.The aggregate conception connects the very fact of the existence of cosmic rays with the continued star-formation process in Galaxy.     

‘Dead’ pulsars: Cosmic-ray sources

Dead pulsars outnumber live pulsars by a factor of 10⁴. It is estimated that there are 3×10⁹ of them in our Galaxy. The exospheres of the atmosphere of dead pulsars are characterised by cosmic-ray energies per particle, as the result of accretion of cold particles from interstellar space. Velocities of particles in the exosphere tend to be Maxwellianised by collisions there. The temperature of the exosphere from which particles escape is of the order of 10¹² K while the temperature of the photosphere closer to the surface of the pulsar is of the order of 10⁷ K. Collisions in the exosphere result in Jeans's type escape of cosmic rays with GeV energies at infinity. Two braod ranges of conditions for the exospheres are considered (a) with no magnetic fields involved, and (b) with magnetic fields. Similar conclusions are reached regarding the escape of cosmic rays. Conditions are delineated such that the exospheres of dead pulsars might be major sources of cosmic rays.Paper dedicated to Professor Hannes Alfvén on the occasion of his 80th birthday, 30 May 1988.     

The development and production of new,non-standard methods of observations with the radio telescope RATAN-600

The recent modernization of the RATAN-600 radio telescope at the Special Astrophysical Observatory has provided an opportunity to develop new procedures, called relay and zoned relay, for utilizing the new cone-surface secondary reflector. The geometric area, the horizontal beamwidth spatial resolution, and the permissible radiometer bandwidth are discussed. We are also able to estimate the changes in the sensitivities of the radio telescope-radiometer systems. The new procedures, called relay and zoned relay, allow us to obtain two-dimensional images of radio objects and to track the development of rapidly varying sources in any azimuth.Presented at the CESRA-Workshop on Coronal Magnetic Energy Release at Caputh near Potsdam in May 1994.     

Interstellar depletion anomalies and ionization potentials

Satellite observations indicate that (1) most elements are depleted from the gas phase when compared to cosmic abundances, (2) some elements are several orders of magnitude more depleted than others, and (3) these depletions vary from cloud to cloud. Since the most likely possibility is that the missing atoms are locked into grains, depletions occur either by accretion onto core particles in interstellar clouds or earlier, during the period of primary grain formation. If the latter mechanism is dominant, then the most important depletion parameter is the condensation temperature of the elements and their various compounds. However, this alone is not sufficient to explain all the observed anomalies. It is shown that electrostatic effects—under a wide variety of conditions—can enormously enhance the capture cross-section of the grain. It is suggested that this mechanism can also account for such anomalies as the apparent overabundance of the alkali metals in the gas phase.     

Generalized ‘dependencies’ and parameter variance

The autodependence, (a special case of the — now quite obsolete — dependences, which had been introduced for very specialized astrometric purposes) is proportional to the parameter variance which is the expectation of the variance of the systematic error of a function evaluated with estimated parameters.     

Stockert's chimney — A galactic fountain

A new type of galactic outflow phenomenon has been discovered and published under the name of thermal spur by Mülleret al. (1987). It is argued that this outflow consists of relativistic pair plasma with an admixture of partially ionized hydrogen and cosmic rays, escaping from a large Hii region. This chimney serves as a substantial leak for the cosmic rays, i.e., may be an essential part of the galactic foundtain.     

The abelian higgs sunspot endowed with a local conformal symmetry

We show that the requirement of alocal conformal symmetry of the Abelian Higgs sunspot leads, at least formally, to a complex-valued electromagnetic potential, whose imaginary part is a conformal compensating potential. It is shown that there exists a fundamental difference between conformal and ordinary electromagnetic fields; whereas the ordinary total magnetic flux of a spot is quantized its conformal analogue has to vanish if the Higgs field is to be single-valued. We further stress that such a complex-valued Abelian Higgs field configuration mimics quite well, under certain conditions (all the salient features of) the classical Abelian Higgs sunspot.     

Взаимодействие Быстрых частиц с магнито-гидродинамической турБулентностью

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The charge and energy spectra of heavy cosmic-ray nuclei

A charged particle detector array flown on a high altitude balloon has detected and measured some 3×10⁴ cosmic-ray nuclei withZ12. The charge spectrum at the top of the atmosphere for nuclei withE>650 MeV·n^–1 and the energy spectrum for 650E<1800 MeV·n^–1 are reported and compared with previously published results. The charge spectrum at the source of cosmic rays is deduced from these data and compared with a recent compilation of galactic abundances.     

On quasi-integrable problems. The example of the artificial satellites perturbed by the Earth's zonal harmonics

With the Hamiltonian parameters developed for the two-fixed-centers problem a simple and very accurate expression of the quasi-integral can be given for the motion of artificial satellites perturbed by the Earth's zonal harmonics. This motion can be considered as integrable.A theoretical analysis shows that Hénon's semi-ergodic regions or chaotic regions are extremely small in this problem, and almost all orbits are of the regular or quasi-periodic type. Furthermore, the relative difference between the true motion and the corresponding integrable motion remains forever less than 10^–14 for all regular orbits even in the vicinity of critical inclinations.For chaotic orbits this very small difference remains verified at least for centuries, nevertheless there are some exceptional orbits that finally diverge from the integrable model.     

Магнитогидро динамическая ротационная модель взрыва сверхновой

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Interstellar clouds and the formation of stars

Part I gives a survey of the drastic revision of cosmic plasma physics which is precipitated by the exploration of the magnetosphere throughin situ measurements. The pseudo-plasma formalism, which until now has almost completely dominated theoretical astrophysics, must be replaced by an experimentally based approach involving the introduction of a number of neglected plasma phenomena, such as electric double layers, critical velocity, and pinch effect. The general belief that star light is the main ionizer is shown to be doubtful; hydromagnetic conversion of gravitational and kinetic energy may often be much more important.In Part II the revised plasma physics is applied to dark clouds and star formation. Magnetic fields do not necessarily counteract the contraction of a cloud; they may just as well pinch the cloud. Magnetic compression may be the main mechanism for forming interstellar clouds and keeping them together.Part III treats the formation of stars in a dusty cosmic plasma cloud. Star formation is due to an instability, but it is very unlikely that it has anything to do with the Jeans instability. A reasonable mechanism is that the sedimentation of dust (including solid bodies of different size) is triggering off a gravitationally assisted accretion. A stellesimal accretion analogous to the planetesimal accretion leads to the formation of a star surrounded by a very low density hollow in the cloud. Matter falling in from the cloud towards the star is the raw material for the formation of planets and satellites.The study of the evolution of a dark cloud leads to a scenario of planet formation which is reconcilable with the results obtained from studies based on solar system data. This means that the new approach to cosmical plasma physics discussed in Part I logically leads to a consistent picture of the evolution of dark clouds and the formation of solar systems.     

New kinds of asymmetric periodic orbits in the restricted three-body problem

The procedure of numerical ascent from families of planar to three-dimensional periodic orbits and the subsequent descent to the plane is proved efficient in determining new families of planar asymmetric periodic orbits in the restricted three-body problem. Two such families are computed and described for values of the mass parameter for which it has been found that they exist. Two new families of three-dimensional asymmetric periodic orbits are also presented in this paper.     

Угловые Флуктуации Реликтового излучения, порождаемые космологической турбу лентностью

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Dynamical and kinematical near homoaxial rotations suitable for representation of nonuniformly rotating stars with extended atmospheres

In this paper, a nontrivial velocity tensor is suitably defined to represent in the common frame the so-called classes of dynamical and kinematical near homoaxial rotations of a deformable finite material continuum. These classes have simple and interesting physical interpretation, especially for treating of nonuniform rotation and its applications to astrophysics. Some important subclasses and derived classes (in the sense of related superclasses) are also discussed.Two coordinate systems are further introduced, one of which rotates uniformly while the other rotates nonuniformly, the latter defined by means of a generalized orthogonal coordinate transformation. Suitable conditions are then given, asserting that the above systems are preferred in the sense of preserving the motion of the continuum in its inertial class.Finally, the required concepts of homotropy and distributivity are defined and the method, by which the established mathematical framework will be subsequently used in applications, is discussed.     

On the stability of small quasiperiodic motions in the hamiltonian systems

Orbital stability of quasiperiodic motions in the many dimensional autonomic hamiltonian systems is considered. Studied motions are supposed to be not far from equilibrium, the number of their basic frequencies may be not equal to the number of degrees of freedom, and the procedure of their construction is supposed to be converged. The stability problem is solved in the strict nonlinear mode.Obtained results are used in the stability investigation of small plane motions near the lagrangian solutions of the three-dimensional circular restricted three-body problem. The values of parameters for which the plane motions are unstable have been found.

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Neutral hydrogen filaments at high galactic latitudes

Small angular scale twists in Hi filaments identified at high galactic latitudes are associated with the location of enhanced emission features (EEFs), structures that have traditionally been referred to as clouds. It is shown that in these directions the column density of gas is enhanced through geometrical effects because the line-of-sight intersects a greater pathlength when viewing along a segment of filament axis (flux tube) than when the tline-of-sight is more normal to the filament axis. By interpreting the EEFs as isolated entities (clouds) we derive an incorrect impression as regards the properties of interstellar Hi. For example, EEFs are typically a factor of five to ten times deeper than they are wide and, hence, the derived properties of Hi structures that have traditionally been taken to be as deep as they are wide are incorrect. This study leads to questions about the way observations of 21 cm, molecular, and 100 emission are currently being interpreted. It is concluded that much of what is observed to be cloud structure in the interstellar medium (except in regions directly associated with star formation) is telling us about geometry of filaments and not about the physics of clouds, The very notion of an interstellar cloud may have outlived its usefulness and previous work that has attempted to account for these structures in terms of gravitational stability or pressure equilibrium has to be reconsidered in the light of the existence of complex patterns of filamentary structure, not only in the Hi distribution but also of interstellar cirrus defined by 100 emission.     

Аккреция вещества с магнитным полем на коллапсирующую звезду. II. Самосогласованная стационарная картина

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Hubble sequence,angular momenta and time-scales of the early evolution of galaxies

The empirical evidence for a connection between type and relative angular momentum of galaxies is reviewed and some constraints for the theoretical explanation are discussed.

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