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ТЕМП РОСТА СВЕРХМАССИВНЫХ ЧЕРНЫХ ДЫР И ЕГО ЗАВИСИМОСТЬ ОТ МАССЫ ЗВЕЗДНОГО НАСЕЛЕНИЯ ГАЛАКТИК В СОВРЕМЕННУЮ ЭПОХУ
Письма в Астрономический журнал. 2021. Т. 47. № 8. С. 537–556.
Prokhorenko S. A., Sazonov S.
Plavin A., R.A. Burenin, Kovalev Y. Y. et al., Journal of Cosmology and Astroparticle Physics 2024 Vol. 2024 No. 5 Article 133
Bright blazars were found to be prominent neutrino sources, and a number of IceCube events were associated with them. Evaluating high-energy photon emission of such blazars is crucial for better understanding of the processes and regions where neutrinos are produced. Here, we focus on hard X-ray emission observed by the SRG/ART-XC telescope, by the Swift/BAT ...
Added: May 15, 2025
S. A. Prokhorenko, S. Yu. Sazonov, Gilfanov M. R. et al., Monthly Notices of the Royal Astronomical Society 2024 Vol. 528 No. 4 P. 5972–5989
We examine the long-term (rest-frame time scales from a few months to ∼20 years) X-ray variability of a sample of 2344 X-ray bright quasars from the SDSS DR14Q Catalogue, based on the data of the SRG/eROSITA All-Sky Survey complemented for ∼7% of the sample by archival data from the XMM-Newton Serendipitous Source Catalogue. We characterise variability by a structure ...
Added: February 1, 2024
Быков С. Д., Бельведерский М. И., Гильфанов М. Р., Письма в Астрономический журнал 2022 Т. 48 № 11 С. 765–777
We present a method for the optical identification of sources detected in wide-field X-ray sky surveys. We have constructed and trained a neural network model to characterise the photometric attributes of the populations of optical counterparts of X-ray sources and optical field objects. The photometric information processing result is used for the probabilistic cross-match of ...
Added: May 24, 2023
Бельведерский М. И., Быков С. Д., Гильфанов М. Р., Письма в Астрономический журнал 2022 Т. 48 № 12 С. 839–851
We have classified the X-ray sources detected by the SRG/eROSITA telescope in the deep Lockman Hole survey. The goal of the classification has been the separation of the sources into Galactic and extragalactic objects. For this purpose, we have used the results of our previous cross-match of Xray sources with optical catalogs. For the classification ...
Added: May 19, 2023
Gorban A., Мольков С. В., Цыганков С. С. et al., В кн.: XIX Конференция молодых учёных «Фундаментальные и прикладные космические исследования» ИКИ РАН, Москва, 13–15 апреля 2022 г.: М.: ИКИ РАН, 2022. С. 34–36.
Added: December 12, 2022
Gorban A., Lutovinov A., Мольков С. В. et al., Письма в Астрономический журнал 2022 Т. 48 № 12 С. 861–868
Представлены результаты исследования рентгеновского пульсара IGR J21343+4738 по данным наблюдений обсерваториями NuSTAR, Swift и СРГ в широком диапазоне энергий 0.3–79 кэВ. Отсутствие особенностей поглощения в энергетических спектрах источника, как усредненном, так и фазово-разрешенных, позволило оценить верхний и нижний пределы на магнитное поле нейтронной звезды в двойной системе B < 2.5 × 10^11 Гс и B ...
Added: December 12, 2022
Gorban A., Molkov S. V., Tsygankov S. S. et al., , in: Astronomy at the epoch of multimessenger studies. Proceedings of the VAK-2021 conference, Aug 23–28, 2021.: Yanus-K, 2022. P. 279–279.
We present the results of our spectral and timing analysis of the emission from the transient X-ray pulsar XTE
J1946+274 based on observations by the NuSTAR in the broad energy range 0.3–79 keV and Swift/XRT in the range
0.2–10 keV ...
Added: December 12, 2022
Biryukov A., Abolmasov P., Monthly Notices of the Royal Astronomical Society 2021 Vol. 505 No. 2 P. 1775–1786
The rotation of a magnetized accreting neutron star (NS) in a binary system is described by its spin period and two angles: spin inclination α with respect to the orbital momentum and magnetic angle χ between the spin and the magnetic moment. Magnetospheric accretion spins the NS up and adjusts its rotation axis, decreasing α ...
Added: October 31, 2022
Gorban A., Мольков С. В., Цыганков С. С. et al., Письма в Астрономический журнал 2022 Т. 48 № 4 С. 279–289
The results of the broadband spectral and timing study of the transient X-ray pulsar GRO J2058+42 in a wide energy range at a low luminosity Lx ≃ 2.5 × 10^36 erg s^−1 are reported. The data revealed that the pulse profile and pulse fraction of the source are significantly changed in comparison with previous NuSTAR ...
Added: June 16, 2022
Gorban A., Мольков С. В., Цыганков С. С. et al., Письма в Астрономический журнал 2021 Т. 47 № 6 С. 416–427
We present the results of our spectral and timing analysis of the emission from the transient X-ray pulsar XTE J1946+274 based on the simultaneous NuSTAR and Swift/XRT observations in the broad energy range 0.3–79 keV carried out in June 2018 during a bright outburst. Our spectral analysis has confirmed the presence of a cyclotron absorption ...
Added: November 18, 2021
Lutovinov A., Monthly Notices of the Royal Astronomical Society: Letters 2018 Vol. 479 No. 1 P. L134–L138
We report on the monitoring of the final stage of the outburst from the first Galactic ultraluminous X-ray pulsar Swift J0243.6+6124, which reached ˜40 Eddington luminosities. The main aim of the monitoring program with the Swift/XRT telescope was to measure the magnetic field of the neutron star using the luminosity of transition to the `propeller' ...
Added: November 1, 2018
Lipunova G. V., Malanchev K., Shakura N. I., , in: Accretion Flows in Astrophysics.: Springer International Publishing, 2018. Ch. 1 P. 1–106.
Accretion discs are powerful energy factories in our Universe. They effectively transform the potential energy of gravitational interaction to emission, thereby unraveling the physics of distant objects. This is possible due to the presence of viscosity, driven by turbulent motions in accretion discs. In this chapter, we describe the equations for disc accretion in the ...
Added: October 26, 2018
Shakura N. I., Lipunova G. V., Malanchev K. et al., Springer International Publishing, 2018.
This book highlights selected topics of standard and modern theory of accretion onto black holes and magnetized neutron stars. The structure of stationary standard discs and non-stationary viscous processes in accretion discs are discussed to the highest degree of accuracy analytic theory can provide, including relativistic effects in flat and warped discs around black holes. ...
Added: October 26, 2018
Oknyansky V., Malanchev Konstantin L., Gaskell C. M., , in: Revisiting narrow-line Seyfert 1 galaxies and their place in the Universe (NLS1-2018), 9-13 April 2018, Padova Botanical Garden, ItalyIssue 328: Proceedings of Science.: Trieste: Scuola Internazionale Superiore di Studi Avanzati (SISSA), 2018. Ch. 12 P. 1–6.
Two major challenges to unification schemes for active galactic nuclei (AGN) activity are the existence of Narrow-Line Seyfert 1s (NLS1s) and the existence of changing-look (CL) AGNs. AGNs can drastically change their spectral appearance in the optical (changing their Seyfert type) and/or in the X-ray region. We illustrate the CL phenomenon with our multi-wavelength monitoring ...
Added: October 26, 2018
Malanchev K., Journal of Physics: Conference Series 2016 Vol. 675 No. 3 P. 1–4
We describe phenomenon of X-ray Novae in a model of non-stationary accretion α-disk with account for irradiation and vertical convection in outer disk region. We extended the commonly used disk vertical structure model by adding viscous turbulent energy generation in mixing length theory. This model was used to simulate both optical and X-ray light curves ...
Added: February 1, 2018
Pozanenko A. S., Barkov M. V., Minaev P. Y. et al., Astrophysical Journal Letters 2018 Vol. 852 No. 2 P. 1–18
We present our observations of electromagnetic transients associated with GW170817/GRB 170817A using optical telescopes of Chilescope observatory and Big Scanning Antenna (BSA) of Pushchino Radio Astronomy Observatory at 110 MHz. The Chilescope observatory detected an optical transient of ∼19m on the third day in the outskirts of the galaxy NGC 4993; we continued observations following ...
Added: January 29, 2018
Буренин Р. А., Ревнивцев М. Г., Ткаченко А. Ю. et al., Письма в Астрономический журнал 2016 Т. 42 С. 240–250
A sample of cataclysmic variables (CVs) detected among the X-ray sources of the 400 square degree (400d) survey performed based on ROSAT pointings is presented. A technique for selecting CVs among the X-ray sources using additional optical and infrared data, based on Sloan Digital Sky Survey andWISE data, is described. We present the optical observations ...
Added: January 28, 2018
Буренин Р. А., Sazonov S., Письма в Астрономический журнал 2016 Т. 42 № 5 С. 277–294
We have compiled a catalog of 903 candidates for type 1 quasars at redshifts 3 < z < 5.5 selected among the X-ray sources of the "serendipitous" XMM-Newton survey presented in the 3XMMDR4 catalog (the median X-ray flux is ≈5 × 10-15 erg s-1 cm-2 in the 0.5-2 keV energy band) and located at high ...
Added: January 27, 2018
Буренин Р. А., Sazonov S., Письма в Астрономический журнал 2017 Т. 43 № 3 С. 159–169
We present the results of optical spectroscopy for 19 quasar candidates at photometric redshifts z phot ≳ 3, 18 of which enter into the Khorunzhev et al. (2016) catalog (K16). This is a catalog of quasar candidates and known type 1 quasars selected among the X-ray sources of the 3XMM-DR4 catalog of the XMM-Newton serendipitous ...
Added: January 27, 2018
Malanchev K. L., Postnov K. A., Shakura N. I., Monthly Notices of the Royal Astronomical Society 2017 P. 410–417
The vertical structure of stationary thin accretion discs is calculated from the energy balance equation with heat generation due to microscopic ion viscosity η and electron heat conductivity κ, both depending on temperature. In the optically thin discs it is found that for the heat conductivity increasing with temperature, the vertical temperature gradient exceeds the ...
Added: October 30, 2017
Lipunova G. V., Malanchev K. L., Monthly Notices of the Royal Astronomical Society 2017 Vol. 468 No. 4 P. 4735–4747
We investigate the viscous evolution of the accretion disc in 4U 1543-47, a black hole binary system, during the first 30 d after the peak of the 2002 burst by comparing the observed and theoretical accretion rate evolution \dot{M}(t). The observed \dot{M}(t) is obtained from spectral modelling of the archival Proportional Counter Array aboard the ...
Added: October 30, 2017