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1.
CCD narrow band imagery of the southern barred spiral NGC 613 has been obtained in the light of H, H, [Oiii] 5007 Å, [Oii] (3726+29) Å and continua at 3765, 5230, and 6500 Å. Absolute fluxes have been obtained for the lines H and [Oiii] 5007 Å and continua at 5230 and 6500 Å. Distribution of ages, monochromatic colour vs absolute brightness and [Oiii]/H are discussed. 相似文献
2.
Gerrit L. Verschuur 《Astrophysics and Space Science》1991,185(2):305-332
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. 相似文献
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Sudden brightening of FeII and Balmer (H and H) lines of X Oph was observed on 28–29 May, 1986. Equivalent width of FeII and H lines increased by a factor of two and that for H line by a factor of four, during the brigtening phase of the star. This brightening phenomena has been explained in the framework of Coronal Radiative Instability. 相似文献
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, , , , . , . , () (), , , . — . 相似文献
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M. N. Stoyanova 《Solar physics》1970,15(2):349-355
A new spectroscopic method of deriving the three-dimensional information (escalation) worked out at the Pulkovo Observatory was applied to observations of solar faculae. The size of the investigated area was 70 × 18. Two series of spectra were obtained simultaneously in four spectral regions (H, D1,2, (Nai), H, and H, K (Caii)) with a quadruple-camera spectrograph attached to the second horizontal solar telescope at Pulkovo on 13 August, 1968.It was found from the analysis of the maps of brightness distribution in the cores of the lines and continuum that the facular emission lies in ropes which incline to the solar surface. 相似文献
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, — . , , . , , . 相似文献
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В. М. Чаругин 《Astrophysics and Space Science》1975,37(2):441-447
, . N/E, E
r, (E
r)=1. , (, ) . . 相似文献
9.
Г. А. ГурзадЯн 《Astrophysics and Space Science》1979,62(1):55-66
, oqn ANS (1500–3300 Å) , I , 3–15 . , <2000 Å nepexo , 1.5 MB . 0 , . . 相似文献
10.
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English translation will appear in the next issue ofAstrophys. Space Sci.
Receipt delayed by postal strike in Great Britain 相似文献
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 相似文献
11.
Р. М. Мурадян 《Astrophysics and Space Science》1980,69(2):325-337
, J=(m/m
p)1+1/n
, n=2 , n=3 , . , . , , . - wc m
P, G c . -. 相似文献
12.
V. A. Brumberg L. S. Evdokimova V. I. Skripnichenko 《Celestial Mechanics and Dynamical Astronomy》1975,11(1):131-138
Based on a general planetary theory, the secular perturbations in the motion of the eight major planets (excluding Pluto) have been derived in polynomial form. The results are presented in the tables. The linear terms of second order with respect to the planetary masses and the nonlinear terms of first order up to the fifth (and partly seventh) degree with respect to eccentricities and inclinations were taken into account in the right-hand members of the secular system. Calculations were carried out by computer with the use of a system that performed analytic operations on power series with complex coefficients.
qA ( ). . ( ) . .相似文献
13.
, ii (2000–3000 Å) i . , i . i (. 2). i i i i + ( 7–10). ii (. 13). ii i i (, 2400 Å) (. 14 15). i i i , iu , i (. 1). i i ii i i . . 相似文献
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Introduction of the O+++H0O++H+ charge exchange rate suggested by Butler, Bender and Dalgarno leads to theoretical nebular models that differ from those previously computed in several important respects. Different elemental abundances, bluer central star energy distributions, and truncated (material limited) models are required. If the argon abundance is fixed from the 7135 [Ariii] line intensity, 4740 [Ariv] is invariably predicted to be much too strong. Better atomic parameters, together with improved charge exchange rates for other ions, and more accurate dielectronic recombination rates may alleviate the situation. 相似文献
16.
From spectroscopic observations of the emission lines H, 4959 and 5007[Oiii], H, 6584[Nii], 6717 and 6731[Sii] and some interferometric data in H and [Nii] it was established that NGC 6164 and NGC 6165 have characteristics of normal Hii regions for Ne and Te. They are embedded in a very tenuous medium nearly coincident with the Strömgren sphere of the central star HD 148937, corresponding to the outer peripheral structure described by Westerlund. Variations of the relative abundances of N, O, and S are discussed. 相似文献
17.
, , , 11 , . , , . 11, , , 5×10–6–5×10–4 ( (2.5–5)×10–7). , 11 . , . 相似文献
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R. Mewe J. Heise E. H. B. M. Gronenschild A. C. Brinkman J. Schrijver A. J. F. den Boggende 《Astrophysics and Space Science》1976,42(1):217-222
With the soft X-ray detector (0.2–0.284 keV) aboard the Astronomical Netherlands Satellite (ANS) we have searched for X-ray emission from hot star coronae and peculiar stars. On Sirius ( CMa) and Capella ( Aur) X-ray emission has been measured at 6 and 5 level, respectively, above background. In all other cases the search revealed no evidence for soft X-ray emission. Upper limits to the luminosities of about 25 star coronae (main-sequence stars, (sub)giants, and supergiants) and of 4 peculiar stars ( Sco, Lyr, P Cyg, and Car) have been obtained.Paper presented at the COSPAR/IAU Symposium on Fast Transients in X-and Gamma-Rays, held at Varna, Bulgaria, 29–31 May, 1975. 相似文献
20.
В. А. Сарычев В. В. Саэонов V. A. Sarychev V. V. Sazonov 《Celestial Mechanics and Dynamical Astronomy》1977,15(1):75-98
, ; . , , , , . . . -. . .
The stability of the stationary motions of a spin-stabilized satellite is investigated using the Lyapunov second method. The nutating motion of the satellite is damped by a special-purpose device. In case the damping device consists of several independent dampers with one degree of freedom little affecting the satellite motion, their optimal parameters ensuring a maximal rate of damping the nutating motion of the satellite are determined with the hypothesis of resonance adjustmentsof the dampers. The Krylov-Bogolyubov method is used to investigate the influence of external moments on the motion of the satellite rotation axis.相似文献