Bubukin, I. T.; Rakut’, I. V.; Agafonov, M. I.; Pankratov, A. L.; Troitskii, A. V.; Lapchenko, V. A.; Gorbunov, R. V.; Zinchenko, I. I.; Nosov, V. I.; Vdovin, V. F., E-mail: bubn@nirfi.unn.ru2019
AbstractAbstract
[en] The results of astroclimate research at the Kara-Dag radioastronomical station (Crimea) from July 22 to September 21, 2017, are presented. The algorithms for processing the data obtained by the atmospheric profile method are analyzed. The broad bands of the MIAP-2 receivers are shown to lead to a non-cosecant dependence of the antenna temperatures on viewing angle. The absorption calculation from three zenith angles by the least-squares method and a reference region with a brightness temperature close to the air temperature is optimal. The patterns of change in atmospheric transparency parameters and their connection with the climatic peculiarities of the observing site are considered. The existing atmospheric circulation is shown to create favorable conditions for nighttime astronomical observations in the millimeter wavelength range on the territory of the Kara-Dag station. Alternative and cheaper approaches to reducing the influence of atmospheric moisture on the measurements in this range than the existing trends are proposed. The first approach consists in choosing a location in a zone with a suitable wind rose and a relief leading to the replacement of moist warm air by dry cold one, for example, in the zones of such local winds as a bora. The second approach suggests the introduction of atmospheric parameter measurements by radiometric methods and allowance for their influence in a real time scale. Since the results obtained are based on limited statistics, they are preliminary ones and stimulate further systematic measurements at Kara-Dag.
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Copyright (c) 2019 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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Journal of Experimental and Theoretical Physics; ISSN 1063-7761; ; CODEN JTPHES; v. 129(1); p. 35-45
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Agafonov, M. I.; Karitskaya, E. A.; Sharova, O. I.; Bochkarev, N. G.; Zharikov, S. V.; Butenko, G. Z.; Bondar’, A. V.; Bubukin, I. T., E-mail: agfn@nirfi.unn.ru2018
AbstractAbstract
[en] 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 (Vx, Vy) section, where the velocity component perpendicular to the orbital plane Vz 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 Vz ~ 300 km/s and with Vx, Vy 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.
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Copyright (c) 2018 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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Astronomy Reports (Online); ISSN 1562-6881; ; v. 62(3); p. 225-237
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Agafonov, M. I.; Karitskaya, E. A.; Sharova, O. I.; Bochkarev, N. G.; Zharikov, S. V.; Butenko, G. Z.; Bondar’, A. V.; Sidorov, M. Yu., E-mail: agfn@nirfi.unn.ru2018
AbstractAbstract
[en] The results of a 3D Doppler tomography analysis for the X-ray binary system Cyg X-1 in the HeII λ 4686 Å line are presented. Information about the motions of gaseous flows outside the orbital plane has been obtained for the first time. Line profiles obtained in June 2007 on the 2-m telescope of the Terskol Branch of the Institute of Astronomy (Russia) and on the 2.1-m telescope of the National Astronomical Observatory of Mexico were used. A detailed analysis of these spectral data is presented: the distribution of the data in time, distribution of orbital phases for the projections, comparison of the line profile shapes for the data from two observatories. The geometry of the total transfer function obtained in the reconstruction is considered. The possibility of applying the profiles obtained to realize 3D tomography is justified. The resolution of the constructed 3D tomogram in velocity space is 60 × 60 × 40 km/s for Vx, Vy, Vz. Fifteen cross sections for 15 different Vz values perpendicular to the orbital plane are presented. The intensity distributions corresponding to the velocities of gaseous structures in the binary system are obtained. The reconstruction was realized using the radio-astronomical approach, developed for solving problems in tomography with a limited number of projections.
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Copyright (c) 2018 Pleiades Publishing, Ltd.; Country of input: International Atomic Energy Agency (IAEA)
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Journal Article
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Astronomy Reports (Online); ISSN 1562-6881; ; v. 62(2); p. 89-102
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