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1.
A limb, two-ribbon H flare on June 4, 1991, associated with a white-light flare and followed by an emission spray and post-flare loops, is studied. A region of rapidly enhanced brightness at the bottom of the H ribbon above the white-light flare is revealed. The energy released by the white-light flare at eff = 4100 is estimated to be about 1.5 × 1028 erg s–1. 相似文献
2.
Using the flux-transport equation in the absence of sources, we study the relation between a highly peaked polar magnetic field and the poleward meridional flow that concentrates it. If the maximum flow speed
m greatly exceeds the effective diffusion speed /R, then the field has a quasi-equilibrium configuration in which the poleward convection of flux via meridional flow approximately balances the equatorward spreading via supergranular diffusion. In this case, the flow speed () and the magnetic field B() are related by the steady-state approximation () (/R)B()/B() over a wide range of colatitudes from the poles to midlatitudes. In particular, a general flow profile of the form sin
p
cos
q
which peaks near the equator (q p) will correspond to a cos
n
magnetic field at high latitudes only if p = 1 and
m = n /R. Recent measurements of n 8 and 600 km2 s–1 would then give
m 7 m s–1. 相似文献
3.
A model of interplanetary and coronal magnetic fields 总被引：5，自引：0，他引：5
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. 相似文献
4.
A. Keith Pierce 《Solar physics》1992,139(1):1-12
In this paper the absolute limb effect for a number of Fraunhofer lines observed at the McMath Solar Observatory is given. Results, uncorrected for scattered light, are given for the following lines: Fei
37334.9, 3735.3, 5123.7, 5250.2, 5434.5, 6678.0, and 8886.6. Additional lines observed are five lines of CN 3876.3–3880.0, two lines of Cai
6161.3 and 6162.2, one line of Nai, 6160.7, and one CN line (7957.0) of the red system.Operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation. 相似文献
5.
, (DM) (RM). , DM RM N
e
= n
e
ds. M
e
= n
e
H cos ds ; . Lerche (1970a, b) , DM RM N
e
M
e
. . 相似文献
6.
M. E. Gedalin J. G. Lominadze E. G. Tsikarishvili 《Astrophysics and Space Science》1991,175(2):291-310
The anisotropic structure of the relativistic stellar wind is investigated. Both relativistic fluid velocity and relativistic temperature are taken into account. General analysis is carried out in the curvilinear coordinates and the generalization of the dispersion equation is obtained. The topological structure of the individual field lines is the same as in the spherically-symmetric case, except the fact that the magnetic field dependence on distance cannot be establisheda priori. The interaction between neighbouring field lines brings the dependence on the transverse coordinate, numbering the field lines. This dependence leads to the establishing of a new constraint on the global flow topology. The two-dimensional wind structure is analyzed, with the constraint taken into account, in the large distances limit, using the asymptotic expansion into ther
–1 power series. In the lowest order approximation the constraint reduces to a new global constant of motion. This constant causes the splitting of the two solution families. 相似文献
7.
Simple self-consistent models for non-neutral current sheets are considered. Characteristics of high-temperature turbulent current sheets (HTCS) with a small transverse component of magnetic field are determined for conditions in the solar corona. The energy output of such an HTCS is much larger than that of a neutral sheet. This makes it possible to consider the HTCS as an energy source not only in long-lived X-ray loops but also in flaring loops during the not or main phase of a flare. In this case, the magnetic reconnection velocity agrees with the observed velocity of the loop rise. Thus, these phenomena can be interpreted as a result of magnetic reconnection, for example, between new flux emerging from under the photosphere and an old magnetic field.The role of a longitudinal magnetic field in a current sheet is less important for HTCS. As a result of the compression of a longitudinal field, there appears an electric current circulating around the sheet. This current may induce strong Joule heating, if the compression is large. This additional heating is realized because of the annihilation of the main component, not the longitudinal component of magnetic field. The effect is small for HTCS, but may be significant for preflare current sheets. 相似文献
8.
A. G. Sokolsky 《Celestial Mechanics and Dynamical Astronomy》1978,17(4):373-394
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.
. , , . . , . , .相似文献
9.
The observed distribution of waiting times t between X-ray solar flares of greater than C1 class listed in the Geostationary Operational Environmental Satellite (GOES) catalog exhibits a power-law tail (t) for large waiting times (t>10hours). It is shown that the power-law index varies with the solar cycle. For the minimum phase of the cycle the index is =–1.4±0.1, and for the maximum phase of the cycle the index is –3.2±0.2. For all years 1975–2001, the index is –2.2±0.1. We present a simple theory to account for the observed waiting-time distributions in terms of a Poisson process with a time-varying rate (t). A common approximation of slow variation of the rate with respect to a waiting time is examined, and found to be valid for the GOES catalog events. Subject to this approximation the observed waiting-time distribution is determined by f(), the time distribution of the rate . If f() has a power-law form for low rates, the waiting time-distribution is predicted to have a power-law tail (t)–(3+) (>–3). Distributions f() are constructed from the GOES data. For the entire catalog a power-law index =–0.9±0.1 is found in the time distribution of rates for low rates (<0.1hours
–1). For the maximum and minimum phases power-law indices =–0.1±0.5 and =–1.7±0.2, respectively, are observed. Hence, the Poisson theory together with the observed time distributions of the rate predict power-law tails in the waiting-time distributions with indices –2.2±0.1 (1975–2001), –2.9±0.5 (maximum phase) and –1.3±0.2 (minimum phase), consistent with the observations. These results suggest that the flaring rate varies in an intrinsically different way at solar maximum by comparison with solar minimum. The implications of these results for a recent model for flare statistics (Craig, 2001) and more generally for our understanding of the flare process are discussed. 相似文献
10.
The location of H filaments is compared with maps of the photospheric line of sight velocity V
and the magnetic field H
. It is found that (1) H filaments are associated with regions of ¦V
¦ 300m s–1, (2) always both positive as well as negative velocities are present under H structures, (3) stable (long lasting) portion of filaments frequently occur at the position of H
= 0 as well as V
= 0 lines, (4) this association remains valid for the longitudes less than 50° from central meridian. 相似文献
11.
H. I. Abdussamatov 《Solar physics》1980,65(1):197-203
The velocity field in a large complex sunspot is investigated in Fe i 6302.5 Å and in H with a spatial resolution of about 2.5. The Evershed flow is almost parallel to the solar surface. For the inclination angle between the velocity and the horizontal = 4.4°±1.3° is estimated; = 11° is the definite upper limit. 相似文献
12.
Janina Krempeć 《Astrophysics and Space Science》1970,6(1):131-140
The coefficients of correlation between spectroscopic data published by Yamashita (1967) and others for carbon stars and the statistical population indices calculated for these stars at the Toru Observatory are calculated (Table II). The intensity estimates of Cai 4227 Å, Nai D lines, the C13/C12 ratio, then=n(Li/Ca) index, as well as CN and probably C2 bands are higher in population I carbon stars. The CH(G) band and probably hydrogen (H, H, H) lines as well as Baii 4554 and 4934 Å lines are stronger in population II carbon stars. The photoelectric colour indices, corrected for interstellar reddening do not show significant population effects. They can be used as spectral type equivalents. For a population criterion the CH/CN intensity ratio is proposed. 相似文献
13.
R. V. Isakov A. A. Ruzmaikin D. D. Sokoloff M. V. Faminskaya 《Astrophysics and Space Science》1981,80(1):145-155
The asymptotic properties of a turbulent disk dynamo at large dimensionless numbersR
andR
characterizing the helicity and the differential rotation are analysed. Three types of generations in the dependence of the relations betweenR
andR
are found: 2-dynamo and two types of -dynamo. For each of these types the rates of growth are obtained and the forms of solution are pointed out. Boundaries of the disk dynamo approximation are given. 相似文献
14.
G. N. Doubochine 《Celestial Mechanics and Dynamical Astronomy》1979,19(3):243-262
Résumé Le présent travail est une continuation d'un autre, publié plus tôt (Doubochine, 1970). On montre ici, que les propriétés des mouvements Lagrangiens et Euleriens établies en mécanique céleste classique sont vraies aussi dans les cas plus généraux, envisagés dans le travail indiqué. On montre de plus, que les trajectoires des points en ces mouvements en axes absolus sont les spirales infinies s'enroulant sur les surfaces des cylindres curvilignes infinis.
-- , (, 1970). , , , , , , , . , , , , .相似文献
15.
A. A. Ruzmaikin D. D. Sokoloff V. I. Turchaninoff Ya B. Zelidovich 《Astrophysics and Space Science》1979,66(2):369-384
The simplest dynamo in a thin disk is analysed. It the antisymmetric helicity function (z) (wherez is a coordinate perpendicular to the disk plane) is smooth and limited, then the conditions for generating a magnetic field and the symmetry of the resulting solutions depend only on the form of at the segment (0,h) — whereh is the half-thickness of the disk — and the value of the dimensionless dynamo numberD. When (z) does not change its sign at this segment andD>D
c
(the critical dynamo number), the excitation of non-oscillating even (quadrupole) and oscillating odd (dipole) fields are possible. When (z) changes its sign at the segment indicated, non-oscillating odd magnetic fields can also be excited.The old exact solutions of the disk dynamo are studied and new ones are found. The results can be of importance when applied to the problem of the generation of a magnetic field in galactic and turbulent disks appearing around some X-ray sources. 相似文献
16.
We present a scalar-tensor theory whose weak field limit gives exactly the potential proposed by Fischbachet al. (1986). The three experimental constantsG
, , and are related to three parameters in our theory. At the level of the theory we have obtained the field produced by a source. The way this field should couple with a massive and charged particle (baryonic hypercharge) is a matter beyond the scope of this work. 相似文献
17.
, kT
b
mc
2 . . , , . E
–5, - E
2, mc
2(kT
/mc
2)1/7. , (>2.105
cm
–3) . , -, , . 相似文献
18.
Л. Г. Лукьялов 《Celestial Mechanics and Dynamical Astronomy》1976,13(4):455-464
, . . . .
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.相似文献
19.
, , , , . , , . , , - - ( , ..). - . 相似文献
20.
A flare event occurred which involved the disappearance of a filament near central meridian on 29 August 1973. The event was well observed in X-rays with the AS & E telescope on Skylab and in H at BBSO. It was a four-ribbon flare involving both new and old magnetic inversion lines which were roughly parallel. The H, X-ray, and magnetic field data are used to deduce the magnetic polarities of the H brightenings at the footpoints of the brightest X-ray loops. These magnetic structures and the preflare history of the region are then used to argue that the event involved a reconnection of magnetic field lines rather than a brightening in place of pre-existing loops. The simultaneity of the H brightening onsets in the four ribbons and the apparent lack of an eruption of the filament are consistent with this interpretation. These observations are compared to other studies of filament disappearances. The preflare structures and the alignment of the early X-ray flare loops with the H filament are consistent with the schematic picture of a filament presented first by Canfield et al. (1974). 相似文献