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D. A. Kononov P. V. Kaigorodov D. V. Bisikalo A. A. Boyarchuk M. I. Agafonov O. I. Sharova A. Yu. Sytov D. Boneva 《Astronomy Reports》2008,52(10):835-846
We carried out spectroscopy of the binary SSCyg in the Hα, Hβ, and Hγ lines in its active state in August and December 2006. We have estimated the parameters of the main flow elements contributing to the spectra. Profile variations during the orbital period are analyzed, and a Doppler tomogram computed for the Hα line. We consider the evolution of the line profiles with the development of the outburst. A phenomenological model explaining the observed outburst features is suggested. In this model, the main elements of the flow determining the shape of the spectral lines are the accretion disk, a toroidal shell formed in the inner parts of the disk, an expanding spherical shell around the accreting star, a region in front of the bow shock that forms due to the orbital motion of the disk in the circumbinary envelope, and the surface of the donor star near the inner Lagrange point, L1, which is heated by radiation from the accretor. 相似文献
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"The authors attack what they call 'superurbanism' and 'agglocentrism,' an excessive preoccupation among some Soviet geographers with urbanization and the formation of urban agglomerations. The authors advocate what is known in Soviet geography as a 'unified system of settlement,' meaning a harmonious blend of both urban and rural forms. The 'agglocentrists' are said to derive their ideas from Western models, and the authors [note the growing] disenchantment with excessive urbanism in the West." 相似文献
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M. I. Agafonov E. A. Karitskaya O. I. Sharova N. G. Bochkarev S. V. Zharikov G. Z. Butenko A. V. Bondar’ I. T. Bubukin 《Astronomy Reports》2018,62(3):225-237
This is the second paper in a series dedicated to studies of the X-ray binary Cyg X-1 in the HeII λ 4686 Å line using 3D Doppler tomography. A detailed analysis of the tomogram constructed has made it possible for the first time to obtain information about the motions of gaseous flows including all three velocity components. The observations were obtained in June 2007 at the Terskol Branch of the Institute of Astronomy (Russia) and the National Astronomical Observatory of Mexico. The correctness of the tomographic results and their discussion is analyzed. The results are compared with a 2D Doppler tomogram reconstruction. Model-atmosphere computations of HeII λ 4686 Å line profiles are used to estimate the influence of absorption features of the Osupergiant on the emission structure in the tomogram. The correctness of the 3D solutions is confirmed by the good agreement between the original sequence of spectral data and a control data set computed using the constructed 3D Doppler tomogram. Tomograms constructed using the data of each of the two observatories are compared. The results of the reconstruction for inclinations of the system of 40° and 45° essentially coincide. The maximum absorption (corresponding to the O supergiant) and emission structural features in the 3D tomogram are located in its central (V x , V y ) section, where the velocity component perpendicular to the orbital plane V z is zero. The emission is generated mainly in the outer part of the accretion structure, close to the supergiant. A gaseous stream from the Lagrangian point L1 with its motion close to the orbital plane can be distinguished. Its maximum velocity reaches 800 km/s. The identification of an emission structure with V z ~ 300 km/s and with V x , V y in the velocity interval corresponding to the donor star was unexpected. Its presence may indicate, for example, an outflow of matter from a magnetic pole of the supergiant. 相似文献
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The resolution provided in 3D Doppler tomography is analyzed. The basis for correcting 3D tomographic structures taking into account the influence of the inclination of the structure on the geometry of the summarized transfer function (STF) used in the reconstruction is presented. The same resolution can be achieved along the axis of rotation and in the orbital plane of a system for an inclination of 54°44′. The positions of the centers of structural features in a tomogram should be preserved when correcting for differences in elongation along the main axes due to the difference in resolution along these axes. Examples of simulations used to estimate possibilities for 3D reconstruction in the central sector of inclination angles, and also for values of these angles near the periphery, are presented. A comparison with results obtained using the radioastronomical approach (RA) and the filtered back-projectionmethod testifies that the latter leads to appreciably larger distortions during a 3D reconstruction. The effectiveness of considering two inclinations, as can be realized for precessing systems, is indicated; this can also be useful in other practical applications. 相似文献
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Oceanology - This study was focused on the investigation of the spatiotemporal structure of the local population of the Black Sea bottlenose dolphins and the identification of stable relationships... 相似文献
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Three-dimensional (3D) Doppler tomography is used to study the motions of gas flows in interacting stellar binary systems. This is achieved by applying a reconstruction method developed for few projections tomography, sometimes referred to as the radioastronomical approach (RA). An analysis of the geometry of the spatial arrangement of the aspects during the reconstruction of 3D tomograms using onedimensional profiles without the intermediate stage of constructing two-dimensional sections is presented. A method for estimating possibilities for reconstructing 3D tomograms based on the appearance of the summarized transfer function is proposed and justified. The influence of the inclination of the system on the resolutions along the main axes is considered. The number of aspects required to achieve a quality of the recontruction comparable to 2D versions is estimated. A comparative analysis of possible distortions of 2D and 3D Doppler tomograms in the presence of flow motions extending beyond the orbital plane is carried out. The analysis indicates the advantages of the 3D method. A summary of first observational results taking into account the velocity component perpendicular to the orbital plane of the binary system, V z , is presented. 相似文献
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G. N. Zastenker E. Salerno F. Buehler P. Bochsler M. Bassi Yu. N. Agafonov N. A. Eismont V. V. Khrapchenkov H. Busemann 《Astrophysics》2002,45(2):131-142
One of the important problems in astrophysics is the determination of the abundances of the helium isotopes 3He and 4He in various regions of the universe, since those abundances can provide evidence of the intensities of various possible processes of the production and decay of light elements and can thereby reflect their history. In this paper we describe the procedure and results of the first determination by a direct method of the abundances of helium isotopes in the local interstellar medium surrounding the solar system. The experiment was carried out on the piloted MIR station by the prolonged exposure in open space of specimens of metallic foil with their subsequent return to earth and detailed laboratory mass-spectrometric analysis. As a result, we were able to obtain estimates of the 4He density (about 7.5·10-3 cm-3) and the 3He/4He isotopic ratio (about 1.7·10-4) for the local interst ellar medium. 相似文献