Перегляд за Автор "Ryabov, Myhaylo I."
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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 Atmosphere drag properties of satellite under influence of "space weather"(Odessa I.I. Mechnikov National University, 2009) Koshkin, Nikolay I.; Korobeynikova, E. A.; Ryabov, Myhaylo I. ; Strakhova, Svitlana I.; Sukharev, Artem L.; Кошкин, Николай Иванович; Кошкін, Микола Іванович; Рябов, Михайло ІвановичДокумент Cycles and anti-cycles of solar activity(Одеський національний університет імені І. І. Мечникова, 2016) Ryabov, Myhaylo I.; Рябов, Михайло ІвановичCurrently representation of solar cycles on average monthly data and smoothed values on various indexes from the full solar disk is generally accepted. Such representation creates an illusion of monotone change and perceptions of simultaneity of manifestations of solar activity for all solar disc. At the same time, daily monitoring data reveal the presence of discrete properties of manifestations of solar cycle. They are associated with absence of spots on the Sun in the northern and southern hemispheres at different intervals. This phenomenon is defined as anti-cycle of solar activity. Properties of discreteness of anti-cycles are presented in this paper on "spotless days’ periods". On their basis the appropriate monthly and annual data was received. The basic characteristics of the manifestations of the discreteness of activity anti-cycles had been determined. It noted the «switch effect» of the existence of the solar dynamo. It manifests itself in the rapid transition from a regime of «spotless days» to the regime of continuous generation.Документ Dynamics and evolution complexes of activity on the sun on various phases of 23 cycle(Odessa I.I. Mechnikov National University, 2009) Ryabov, Myhaylo I. ; Lukashuk, S. A.; Рябов, Михайло ІвановичДокумент Flux density evolution of the sources 3C273, 3C279 and 3C454.3 at the frequencies 102 MHz–36.8 GHz(2007) Volvach, A. E.; Volvach, L. N.; Larionov, M. G.; Aller, H. D.; Aller, M. F.; Yurovskiy, Yu. Yu.; Ryabov, Myhaylo I. ; Рябов, Михайло Іванович; Madrid : Consejo Superior de Investigaciones Científicas, Instituto Miguel Asín,The results of long-term monitoring of the sources 3C273, 3C279 and 3C454.3 at 102 MHz–36.8 GHz are presented. Numerical analysis of irregular temporal rows of the integral fluxes allowed us to detect the quasiperiodic constituents of the emission flux variations. The analysis of the parameters of binary black holes in the central regions of non-stationary objects demonstrates that these super-massive objects have an insignificant variation between the sizes of the orbits of partners, and that they are in the stage of evolution different from the time of merging by a period of less than 104 years.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 Motions of the components of AGNS according to VLBI MOJAVE data as indicators of the activity and spatial structure of the jet(Одеський національний університет імені І. І. Мечникова, 2023) Zabora, D.; Ryabov, Myhaylo I. ; Sukharev, A.; Bezrukovs, V.; Bazyey, Oleksandr A.; Базєй, Олександр Анатолійович; Рябов, Михайло ІвановичThe system of ten radio telescopes VLBA (Very Large Baseline Array), with a maximum baseline of about 8,600 km, of the National Radio Astronomy Observatory of the USA (NRAO USA) carries out systematic monitoring observations of about 500 active galactic nuclei (AGN), the results are presented in the MOJAVE database. The resulting angular resolution (~0.47 arcseconds at a frequency of 15.4 GHz) is enough to separate the close surroundings of the AGN and its jet. The results of corresponding observations make it possible to compare the features of movement in the jet with the processes of activity of the AGN, as well as to study its spatial structure. The MOJAVE database contains the spectral densities of the radio fluxes of the AGN, radio images for each epoch of observations at the frequency of 15.4 GHz, and "Separation jet" diagrams (showing the angular separation of the jet components over time). This information makes it possible to study the movement of these components. In this work, a general analysis of movement patterns of the components of the 3C 273 jet was performed. In the published papers of the MOJAVE team, a similar analysis wasn’t presented for all jet’s features.Документ Secular decrease the flux of supernova remnant cas a on monitoring results to radiotelescope "URAN-4" IRA NASU(Одеський національний університет імені І. І. Мечникова, 2015) Gorbynov, A. A.; Ryabov, Myhaylo I.; Panishko, S. K.; Рябов, Михайло ІвановичThis work is dedicated to the study of secular decrease of the flux of young supernova remnant Cas A according to observations by radio- telescope "URAN-4» of Odessa Observatory IRA NASU from 1987 to 2001 years on frequency of 25 MHz. On the investigation base there is a relationship analysis of flux CasA to the "stable" source – radio-galaxy Cyg A (CasA/Cyg A) which is located on a small angular distance. Results of the observations held on RT «URAN- 4» show that there is no noticeable decrease of fluxes in the period 1987-1993, with the relationship ratio (CasA/Cyg A) = 1.5. While considering data from 1987 to 2001 manifested a slight decrease trend in flux equal to 8.4% for the all period. At the same time, according to various investigations the average value flux of Cas A in the interval of frequencies 38-2924 MHz is 0.8% per year. At the meantime in this frequency the range ratio (CasA/Cyg A) has become less than one. Thus, there is a noticable contradiction of secular decrease of the flux Cas A on this radio frequencies in comparison with the predictions of the theory in 1.7% per year.Документ Singular-Spectrum Analysis and Wavelet Analysis of the Variability of the Extragalactic Radio Sources 3C 120 and CTA 102(2016-06) Donskykh, Ganna I.; Ryabov, Myhaylo I. ; Sukharev, Artem L.; Aller, M. F.; Рябов, Михайло ІвановичThis is a study of the variability of the fluxes of radio emission from the quasar CTA 102 and the radio galaxy 3C 120 based on data from the University of Michigan Radio Astronomy Observatory (UMRAO, Ann Arbor). The data were obtained at three frequencies (14.5, 8, and 4.8 GHz) with the 26-m radio telescope. Two mutually complementary methods were used for the analysis: wavelet analysis and singular spectrum analysis. Wavelet analysis is based on the Fourier transform, while singular-spectrum analysis does not use an analyzing function. Long-duration components of the variability in the range of ~4-11 years were found for 3C 120 and ~1.5-3 years, for CTA 102. The short-duration components of the variability are characterized by periods of ~0.7-3.4 years for 3C 120 and ~0.5-0.8 years for CTA 102. These data were also compared with VLBI charts from the MOJAVE archive for studying the evolution of the components in the jets of the quasars studied here.Документ 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 6th Gamow Summer School: Astronomy and Beyond: Astrophysics, Cosmology, Radioastronomy, Astrobiology(2007) Ryabov, Myhaylo I. ; Рябов, Михайло Іванович; Madrid : Consejo Superior de Investigaciones Científicas, Instituto Miguel Asín,Документ The catalog of periods of the variability of blazars 3C120, 3C273, 3C279, 3C345 and 3C454.3 at centimeter and millimeter wavelengths(Odessa I.I. Mechnikov National University, 2009) Volvach, A. E.; Ryabov, Myhaylo I. ; Volvach, L. N.; Sukharev, Artem L.; Aller, H. D.; Aller, M. F.; Рябов, Михайло ІвановичccVariations in the radio flux of 3C120, 3C273, 3C279, 3C345, 3C 454.3 are analyzed using long-term monitoring data at five frequencies from 4.8 to 36.8 GHz obtained at the University ofMichigan Radio Astronomy Observatory and the Crimean Astrophysical Observatory. A spectral analysis of the light curves at the various frequencies reveals the presence of periodic components. Using method of model calculations for each of the found period tested its ability to reproduce the observed flux variability at different frequencies. On the basis of the model calculations presented the catalog of the most reliable periods of flux variable of radio sources.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 main properties of flux variability of extragalactic radio sources bl lac and oj287(Odessa I.I. Mechnikov National University, 2009) Ryabov, Myhaylo I. ; Sukharev, Artem L.; Рябов, Михайло ІвановичДокумент 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.Документ Гамов: физика – космология – генетика(Одесский национальный университет имени И. И. Мечникова, 2019) Рябов, Михаил Иванович; Чернин, А. Д.; Рикун, И. Э.; Рябов, Михайло Іванович; Ryabov, Myhaylo I.Книга о жизни и творческих достижениях выдающегося ученого Георгия Антоновича Гамова. Будучи родом из Одессы, в 1920 г. он становится студентом математического отделения физико-математического факультета Новороссийского университета. На здании главного корпуса Одесского национального университета имени И. И. Мечникова в его честь установлена мемориальная доска.Документ От черных дыр до космической погоды –горизонты международного астрономического сотрудничества(Одесский национальный университет имени И. И. Мечникова, 2021) Рябов, Михайло Іванович; Рябов, Михаил Иванович; Ryabov, Myhaylo I.Сегодня существует немало возможностей, которые еще не получили своего широкого развития. Примером может служить украинского-латвийское сотрудничество в области астрономических и радиоастрономических исследований с Международным Вентспилским радиоастрономическим центром (VIRAC), Институтом радиоастрономии НАНУ (РИ НАНУ) (Одесская обсерватория "УРАН-4") и астрономической обсерваторией ОНУ имени И.И.Мечникова.Документ Словник термінів з радіоастрономії(Одеський національний університет імені І. І. Мечникова, 2017) Рябов, Михайло Іванович; Мурніков, Борис Олександрович; Кабанова, Тамара Іванівна; Ryabov, Myhaylo I.; Murnikov, Borys O.; Kabanova, Tamara I.Наукові дані, отримані за останнє століття, настільки розширили і збагатили уявлення про Всесвіт, що зараз у жодній галузі астрофізики – від фізики Сонця і планет до позагалактичної астрономії – не можна обійтися без радіоастрономічних спостережень. З іншого боку, ці спостереження спираються на досягнення радіофізики та потужну технічну базу, і тим самим стимулюють розвиток науки і техніки. Книга буде корисною не тільки для студентів, котрі вивчають цю дисципліну, а й спеціалістам і студентам суміжних галузей, а також всім, хто цікавиться Всесвітом і методами, що його вивчають.