Перегляд за Автор "Sukharev, A. L."
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Документ ANALYSIS OF THE VARIABILITY AND THE SPECTRUM OF PERIODS OF EXTRAGALACTIC SOURCE OJ 287 IN THE RADIO WAVES(Astroprint, 2013) Donskykh, A.; Ryabov, Myhaylo I.; Sukharev, A. L.; Aller, M. F.; Рябов, Михайло ІвановичWe analyzed long-term monitoring of data flux of extragalactic source OJ 287 obtained at frequencies of 14.5 GHz (1974-2011), 8 GHz (1971-2011), 4.8GHz and (1979-2010), on the RT-26, University of Michigan, USA. Variability of the flux of the radio source was investigated by applying wavelet analysis. There were identified long-period (in the range of 3.6 to 13.6 years) and short (in the range from 1.2 to 1.8 years) components at all studied frequencies and it was determined the time of their existence. The "spectra periods" for each year of observation were built to assess the contribution of individual periods in the formation of the most powerful phase of activity of the radio source. The dynamics of the manifestations of active periods at different frequencies was observed. The obtained data was compared with the results of MOJAVE VLBI monitoring for the period of 1995-2012 years at a frequency of 15.4 GHz. It allowed to investigate the structure of emissions during periods of manifestation activity maxima.Документ Influence of space weather effects on the upper atmosphere according to the drag of artificial earth satellites(Astroprint, 2014) Komendant, V. H.; Koshkin, Nikolay I.; Ryabov, Myhaylo I.; Sukharev, A. L.; Кошкин, Николай Иванович; Кошкін, Микола Іванович; Рябов, Михайло ІвановичThe applying of the method of timefrequency analysis allows to reveal the detailed structure of the manifestations of the influence of the space weather's state on the upper atmosphere of the Earth. The sensitive indicator of such changes are low-orbit satellites. The drag dynamics of five low–orbit satellites was viewed as indicators manifestations of the influence of space weather on the Earth upper atmosphere. The study period includes phases of decay and a long minimum of 23-rd solar cycle, phases of growth and maximum of 24-th solar cycle. In drag dynamics of all the analyzed satellites strongly marked regular drag effects with long periods (2-4 years) and short-period effects with periods less than one year. The satellites with orbital inclinations close to the equator shows periods with trend from 25 days to 1,3 monthsДокумент Study of quasi–periodic variations in drag of artificial satellite during 23–24 solar cycles(Одеський національний університет імені І. І. Мечникова, 2015) Komendant, V. H.; Ryabov, Myhaylo I.; Sukharev, A. L.; Рябов, Михайло ІвановичApply of the method of time-frequency analysis allows to reveal the detailed structure of the manifestations of the influence of the state space weather on the upper atmosphere of the Earth. Sensitive indicators of such changes are low-orbit satellites. The dynamics of drag of nineteen low–orbit satellites was viewed. The study period includes phases of declining and a long minimum of 23rd solar cycle, phases of rise and maximum of 24th solar cycle. In dynamic of inhibition of all the analyzed satellite pronounced regular inhibition effects with extended periods of 2 – 6 years and short-period effects with periods less than one year. In the satellites: 00063, 00165, 25064, 00932 and 00746 – detected periods with trend from 25 – 28 days to 1 – 1.7 months.Документ The change indices of solar and geomagnetic activity and their influence on the dinamics of drag of artificial satellite(Одеський національний університет імені І. І. Мечникова, 2016) Komendant, V. H.; Koshkin, Nikolay I.; Ryabov, Myhaylo I.; Sukharev, A. L.; Кошкин, Николай Иванович; Кошкін, Микола Іванович; Рябов, Михайло ІвановичThe time-frequency and multiple regression analysis of the orbital parameter characterizing the drag of satellites on circular and elliptical orbits with different perigees and orbital inclinations in the atmosphere of the Earth was being conducted in 23-24 cycles of solar activity. Among the factors influencing braking dynamics of satellites were taken: W – Wolf numbers; Sp – the total area of sunspot groups of the northern and southern hemispheres of the Sun, F10.7 – the solar radio flux at 10,7 cm; E – electron flux with energies more than 0,6 MeV и 2 MeV; planetary, high latitude and middle latitude geomagnetic index Ap. In the atmospheric drag dynamics of satellites, the following periods were detected: 6–year, 2.1–year, annual, semi-annual, 27–days, 13– and 11–days. Similar periods are identified in indexes of solar and geomagnetic activity. Dependence of the periods of satellites motion on extremes of solar activities and space weather conditions was conducted.Документ The study of extragalactic sources 3C 446 AND 3C 345 with using the singular spectrum and wavelet analysis(Одеський національний університет імені І. І. Мечникова, 2015) Donskykh, G. I.; Ryabov, Myhaylo I.; Sukharev, A. L.; Aller, M. F.; Рябов, Михайло ІвановичWe investigated the data of monitoring of flux density of extragalactic sources 3С446 and 3C345, which was held on 26-meter radio telescope of University of Michigan at frequencies 14.5, 8 and 4.8 GHz. The data of observations were investigated using singular spectrum analysis and wavelet-analysis. According to the results of wavelet analysis for each year of observations, graphics of “spectra periods” were built to determine the contribution of individual periods in the activity of the radio source. The results obtained with two different methods showed a good correlation between them. For a long time component of the flux the periods of ~ 5 – 9 years were found. For short term components the periods of ~ 1 – 4 years are presented. The results obtained using two different methods were compared with VLBI radio maps, which were obtained by the program MOJAVE. The changes of periods over time are associated with certain physical processes in the system "core – accretion disk – jet" and with appearing of new bright components (knots) in the jet.Документ Using the methods of wavelet analysis and singular spectrum analysis in the study of radio source BL Lac(Astroprint, 2014) Donskykh, G. I.; Ryabov, Myhaylo I.; Sukharev, A. L.; Aller, M. F.; Рябов, Михайло ІвановичWe investigated the monitoring data of extragalactic source BL Lac. This monitoring was held with University of Michigan 26-meter radio telescope. To study flux density of extragalactic source BL Lac at frequencies of 14.5, 8 and 4.8 GHz, the wavelet analysis and singular spectrum analysis were used. Calculating the integral wavelet spectra allowed revealing long-term components (~7-8 years) and short-term components (~ 1-4 years) in BL Lac. Studying of VLBI radio maps (by the program Mojave) allowed investigating features of components movement relatively to the VLBI core. The data of radio astronomy observations were also investigated using singular spectrum analysis. This method can solve the task of allocating trend, detection of periodic components and band-pass filtering (reconstruction of time series from quantity of main components, the last corresponds to individual bands of periods on time-frequency spectra or Fourier spectra). Singular spectrum analysis does not use the analyzing function, so its calculations allow to distinguish various components of investigated series with a high accuracy. To get spectral power distribution depending on time in the studied narrowband components obtained by singular spectrum analysis, short-term Fourier transformation was usedДокумент VARIABILITY OF THE EXTRAGALACTIC RADIO SOURCES 3С120, СТА102, DA55 AND OJ287 ON CENTIMETER WAVES AND ITS CONNECTIONS WITH THE DATA OF VLBI OBSERVATIONS(Astroprint, 2012) Ryabov, Myhaylo I.; Donskykh, A.; Sukharev, A. L.; Aller, M. F.; Рябов, Михайло ІвановичABSTRACT. By data of the long-term monitoring (30-40 years) fluxes of extragalactic radio sources 3C120, CTA102, DA55 and OJ287 received on the RT-26, University of Michigan present results of data processing with use the wavelet analysis. Received analysis of trend and short-time components of the flux density changes in the studied frequencies 14.5, 8 and 4.8 GHz. For each time components on all frequencies found values of main periods and time of their existence, integrated power spectra for the phases activity for radio sources was built. From the results of VLBI observations in sources with long jets (3C120 and CTA102) detected quasi-periodic structures brighter components. Their appearance is linked to the dynamics of the interaction of shock waves in the jet emission from the cores. Quasi-periodic structures in the jet can be formed as a result of a return standing wave.