首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
The large-scale component of the dynamics of local solar source radiation was found according to observations with the radio telescope RATAN-600 by the relay method at wavelengths 2.3 cm and 4.5 cm on 17 July and 29 July, 1981. The local solar sources were identified with groups of spots on the Sun widely separated from each other.Presented at the CESRA-Workshop on Coronal Magnetic Energy Release at Caputh near Potsdam in May 1994.  相似文献   

2.
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.  相似文献   

3.
The reported correlation between the absorption-line of emission-line redshifts of quasars is shown to be due to selection effects and thus to favour neither the intrinsic nor intervening hypotheses for the origin of quasar absorption lines.  相似文献   

4.
Standard UBV light curves of eclipsing binary star GO CYGNUS havebeen presented. These light curves indicate a Lyrae typevariations with circular orbit. The Light curve analysis have beencarried out on three colours U, B and V. The results obtained fromthese analysis represent an occultation solution with r r =1.24.  相似文献   

5.
Formulae containing the elements of the variational matrix are obtained which determine the linear iso-energetic stability parameters of periodic orbits of the general three-body problem. This requires the numerical integration of the variational equations but produces the stability parameters with the effective accuracy of the numerical integration. The procedure is applied for the determination of horizontally critical orbits among the members of sets of vertical-critical periodic orbits of the threebody problem. These critical-critical orbits have special importance as they delimit the regions in the space of initial conditions which correspond to possibly stable three-dimensional periodic motion of low inclination.  相似文献   

6.
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.  相似文献   

7.
The formation of the bump and the black-body cutoff in the cosmic-ray (CR) spectrum arising from the -meson photoproduction reaction in collisions of UHE CR protons with the microwave background radiation (MBR) is studied. A kinetic equation which describes CR proton propagation in the MBR with account of the catastrophic nature of the -meson photoproduction process is derived. The equilibrium CR proton spectrum obtained from the solution of the stationary kinetic equation is in general agreement with the spectrum obtained under assumption of the continuous energy loss approximation. However, the spectra from point sources noticeably differ from those obtained in the continuous loss approximation. Both, the equilibrium and the point source spectra are modified when taking into account the possible deviation of the MBR spectrum from the Planckian one in the Wien region. Thus, for the recently measured MBR spectrum, which reveals an essential excess in the submillimeter region, the black-body cutoff and the preceding bump shift towards lower energies.Deceased, August 13, 1989.  相似文献   

8.
In the quasi-linear theory of pitch angle scattering the power spectrum of magnetic field fluctuations is related to the shape of the pitch angle diffusion coefficient D(), the absolute value of the mean free path , and the rigidity dependence of the mean free path (R). We discuss these relations in detail during the solar particle event of 11 April, 1978 which was observed on HELIOS-2 at a distance of 0.49 AU from the Sun. Magnetic field measurements obtained during the time of the event are used as a basis for the layer model in which the method of particle trajectories in an actually measured field is used to simulate pitch angle diffusion. The values of D() and based on the trajectory simulation for 100 MeV protons (field approach) are compared with results obtained from solar proton data (particle approach) and with predictions from quasi-linear theory based on the additional assumption of the slab model for magnetic field fluctuations (QLT approach). The time of the event is characterized by a high level of field fluctuations, the observed mean free path of about 0.03 AU for 100 MeV protons is smaller than the average value near 1 AU. Results from the field and particle approaches agree surprisingly well. The remaining difference in the mean free path of about a factor of 2 could be due to tangential discontinuities which are measured by the magnetometer, but not seen by the real particles traveling along the average field. The results from the field and QLT approaches based on the same set of magnetic field measurements differ by about a factor of 4. One of the reasons for this discrepancy is that the conditions for resonance scattering are only marginally valid. In addition, the wave vectors representing Alfvén-type fluctuations may not be totally field aligned. This deviation from the slab model would cause an increase of the theoretically predicted mean free path and lead to better agreement with the other two approaches.  相似文献   

9.
A number of suggestive coincidences are found in a purely speculative analogy between the by-products, of a minihole fast evaporation in a plasma, and by-products from flares at magnetospheres. Solar flares might serve as good examples. From an observational point of view our attention is drawn to the considerable extent of the blank time interval existing between known before and after evidences on flares, during which some exotic energy conversion processes could be invoked to explain the large amount of energy released in time-scales that might be very short. We suggest that fundamental progress in the knowledge of energy conversion, processes in flares require observational data with a time resolution several orders of magnitude, better than the currently available data, particularly, for hard X-rays.  相似文献   

10.
A. M. Uralov 《Solar physics》1996,168(2):311-329
An attempt is made to impart a constructive character to the concept of the solar flaremagnetospheric substorm analogy. An idealized scheme for a two-ribbon solar flare in the originally closed magnetosphere of the active region is discussed. The basis is formed by a terrestrial substorm scenario with two active phases (Mishin et al., 1992). While a quadrupole magnetic configuration turns out to be a solar analog of the Earth's magnetosphere. A physical mechanism that sustains the preflare storage phase, is provided by an instability like a stretching instability of the closed geomagnetotail. The storage process is attributed to the emergence into the corona of closed magnetic flux lines in adjacent (to the location of the would-be flare) regions. The flare flash-phase is determined by the change-over of the stretching instability to a disruption instability of a nonstationary (not neutral) current sheet inside the storage zone. The final recovery phase corresponds to the wellknown Pneuman-Kopp model.  相似文献   

11.
One component of a three-fluid adiabatic plasma is under certain conditions contained in a restricted region of space by a large-scale electrostatic field generated within the plasma. The containment is discussed here for plasma consisting of ions and two populations of electrons characterized by different pitch angle distribution functions.The bouncing motion of electrons along open fieldlines between a magnetic mirror and an electrostatic mirror produces a velocity distribution function similar to that generated by bouncing particles on closed fieldlines.  相似文献   

12.
B, V observations of the eclipsing binary RS CVn have been presented. A dip around 0 p . I appears to be a wave minimum which fits well in the Wave minimum phase-time relation, but deviates from the Wave aplitude-time relation, derived for the RS CVn. Either, the Wave amplitude-time relation requires a modification or the amplitude of the wave minmum appears masked by the intrinsic variability of one of the components or by the Sun-spot activity of the system. The colour exhibits variation. The secondary component appears active.  相似文献   

13.
Sunspot associated H-flares and microwave bursts occurring during the period 1972 to 1974 have been examined in relation to the magnetic strength and configurations of the sunspots and sunspot groups (abbreviated as spots). Important results obtained are: (i) percentage occurrences of flares exceeds those of microwave bursts up to a magnetic field strength of 2000 G while the reverse is true for higher field strength of spots, (ii) flare productivity (average number of flares per spot) and also burst productivity are comparatively higher in the case of and types of spots than in the case of other types of spots, (iii) the above productivities are predominantly high when magnetic configuration of spots changes during their life time, and (iv) impulsive type of microwave bursts are more associated with spots having changing type of magnetic configuration.  相似文献   

14.
The stability analysis of several stronglynon-homogeneous, self-gravitating, one-dimensionalunstable equilibrium systems is carried out with the help of numerical techniques. The evolution of the perturbed unstable equilibria is studied by following the motion of the boundary curves of water bag configurations defining the systems.It is found that initial perturbations drive the unstable equilibrium states out of equilibrium at rates depending on the typical scale length of the perturbations : the instability rates increase with .  相似文献   

15.
It is shown that, for the scalar-tensor cosmology (STC) by Jordan-Brans-Dicke (JBD), in general anisotropic solution the oscillatory mixmaster regime near the singularity will be destroyed by the scalar source-free field and replaced by monotonousV 3-collapse into the point or into the line and plane (only in caseG0) even in the presence of the primordial source-free electromagnetic (EM) field.  相似文献   

16.
With the use of X-ray heliographs carried by the satellites Cosmos-166 and Cosmos-230 the height of an X-ray flare was found to be about 20–25 000 km. The regions of the X-ray flares possess a filamentary structure which, during the development of the flares, shows spatial changings with speeds up to 107 cm/sec.  相似文献   

17.
The complete analysis of possible types of non-relativistic and ultra-relativistic motions in the field of the naked singularity of the STGT is given. The problem of the infall of a monochromatic radiation emitter on the naked singularity is studied. In spite of the absence of a freezing effect in the STGT, the naked singularity is not observable, for the brightness of the falling emitter decreases much faster than in the GTR. Atrr g , the trajectory of particles and light are quite similar to that of the GTR, and due to this fact the naked singularity is observationally indistinguishable from a black hole.  相似文献   

18.
The behaviour of the primary and secondary components in a sample of double-lined Algol-type eclipsing binaries in the logg-logT e diagram is analyzed. Our results indicate that the hotter components behave like normal Main-Sequence stars while the effect of irradiation may partly explain the overluminosity of the cool components.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.  相似文献   

19.
We numerically study the bifurcations of two nonlinear maps, with the same linear part, which depend on a parameter namely the Hénon quadratic map and the so called beam-beam map. Many families of periodic orbits which bifurcate from the central family, are studied. Each family undergoes a sequence of period doubling bifurcations in the quadratic map, But the behavior of the beam-beam map is completely different. Inverse bifurcations occur in both maps. But some families of the same type which bifurcate inversely in the quadratic map do not bifurcate inversely in the beam-beam map, even though both maps have common linear part.  相似文献   

20.
The behavior of phase speed for the slow and fast magnetosonic waves is well documented in the literature. Not so well documented is the behavior of the ray direction and its relation to the phase direction — indeed we have not found the ray behavior recorded in most of the standard plasma physics texts. We rectify this situation and point out some of the curiosities associated with the direction of the slow ray relative to the direction of the slow phase wave. These calculations have been performed as a necessary basis for discussion of phase and ray evolution of magnetosonic waves in differentially shearing plasmas, which subject is the topic of a later paper.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号