High energy astrophysics

For the first time in decades, the practical possibilities of wide-ranging multi-wave observation have emerged, involving rapid development and significant discoveries in understanding the nature of both large-scale structures – filaments and their components – galaxies and their clusters. In modern astrophysics, it is important to understand the nature of the galactic nuclei (supermassive black holes with accretion disks, Fig. 1), which actively emit in the X-ray range (see Fig. 2 and 3). It is advisable to study the radiation of extragalactic objects, embracing the entire multi-wave experimental base, using the opportunities to access the data of observations of already completed and active space missions.

Employees and students of the Department of Quantum Field Theory and Cosmomicrophysics have the opportunity to use access to the Virtual Roentgen and Gamma Observatory (VIRGO, virgoua.org) in their research. VIRGO was created by the joint efforts of the Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine and the Taras Shevchenko National University of Kyiv (Department of Quantum Field Theory and Cosmomicrophysics, Department of Astronomy and Space Physics, Astronomical Observatory) and with the financial support of the Geneva Observatory and INTEGRAL Science Data Center (ISDC). The VIRGO-center at the Faculty of Physics was opened on April 18, 2006. Today, the VIRGO-center is equipped with modern computer equipment (see Photos 1 and 2) for efficient and rapid work related to astrophysical research at advanced X-ray and gamma-ray observatories – international scientific infrastructure projects (processing of space mission data, that are available in the center: INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), X-ray Multi-Mirror Mission (XMM-Newton), Chandra X-ray Observatory (Chandra), Fermi Gamma-ray Space Telescope (Fermi), Nuclear Spectroscopic Telescope Array NuSTAR), Swift BAT (Burst Alert Telescope), XRT (X-ray Telescope) and research for Cherenkov Telescope Array (CTA), i.e. it has unique competencies in most areas of space research in the X-ray and gamma range and is actively involved in international cooperation.

Studying of active galaсtic nuclei (AGNs), the problem of quasar classification and analysis of obscured and Compton-thin quasars and their relationship; research of magnetic fields of AGN’s accretion disks and their influence on jet formation, as well as the solution of the equations of magnetohydrodynamics near a supermassive black hole; analysis of TeV blazars (Fermi data processing), cataloging of perspective objects, namely analysis of spectra of blazars in X-ray and gamma ranges, the observation of which may limit the value of magnetic fields in inputs; testing of thermal reprocessing models in the active nuclei of galaxies, where ultraviolet (UV)/X-ray photons are reprocessed by the accretion disk into optical/UV photons are relevant. Another aspect of the activity is the tracking of the movements and behavior of dark matter, which requires studies of the morphology and spectra of galaxies of different types in a wide range of electromagnetic waves.

Fig. 1. Picture a black hole that distorts space-time. A luminous accretion disk is formed around the black hole as a result of rotation and matter falling on it. Here we use the famous image of the Gargantua black hole, obtained by Kip Thorne and Paul Franklin’s Visual Effects Department for “Interstellar” film.

Fig. 2. Image of the galaxy Mrk 273, obtained with the Hubble Space Telescope (original image). Mrk 273 is one of the closest Ultra-Luminous Infrared Galaxy (ULIRG) with an active nucleus (nucleus activity class Seyfert 2), presumably formed by the merger of two galaxies. The selected central region with two visible nuclei was obtained using an OSIRIS infrared spectrograph from the Keck telescope (original image).

Fig. 3. Image of the center of Mrk 273 galaxy in the X-ray range obtained by processing the archival data of the Chandra telescope. It is uncommonly in X-rays to distinguish two active nuclei in one galaxy (For X-ray observations of double- and multiple-nuclei galaxies, it’s good to use the Chandra satellite’s observations, as it has the best available resolution of 0.5”). To obtain the image, 5 observations were used (PID 17700440; PI Veilleux), the total time of which is 200 kiloseconds (55.55 hours).

VIRGO-center, aud. 423, Faculty of Physics

Publications 2021

  1. Zadorozhna L.V., Tugay A.V., Maluy O.I. and Pulatova N.G. X-ray spectral features and classification of selected QSOs, Journal of Physical Studies, 25(4), 4901, 15 pp, (2021); DOI: 10.30970/jps.25.4901
  2. Zadorozhna L.V., Tugay A.V., Shevchenko S.Yu., Pulatova N.G. The Xgal catalog of X-ray galaxies, Kinematics and Physics of Celestial Bodies, vol. 37, issue 3, pp. 149-157, (2021); DOI: 10.3103/S0884591321030077
  3. Pulatova N.G., Tugay A.V., Zadorozhna L.V. The sample of eight LLAGNs: X-ray properties. Proceedings of IAU Symposium 367/ Education and Heritage in the Era of Big Data in Astronomy, December 8-12, 2020, Cambridge University Press, 4 pages, (2021); DOI: 10.1017/S1743921321000168
  4. Tugay A.V., Shevchenko S.Yu., Zadorozhna L.V. Determination of galaxy distribution with statistical moments, Odessa Astronomical Publications. vol. 34. P. 42-45, (2021); DOI: 10.18524/1810-4215.2021.34.244253.
  5. Tugay A., Gugnin O., Pulatova N., Zadorozhna L. Advanced morphology of VIPERS galaxies, Gini, M20 and CAS statistics with detailed analysis of Sersic index, Preprint, April 2021, p.1-29, DOI: 10.13140/RG.2.2.24815.15523.
  6. Tugay A., Gugnin O. , Pulatova N., Zadorozhna L. Advanced morphology of VIPERS galaxies, Preprint, April 2021, p.1-11, DOI: 10.13140/RG.2.2.26320.84489.
  7. Pulatova N.G., Tugay V., Malyi O., Zadorozhna L.V., Lukina O. X-ray galaxies selected from SDSS // Astronomy and Space Physics in the Kyiv University Book of Abstracts. – 2021. – P. 39. http://www.observ.univ.kiev.ua/conference/wp-content/uploads/2021/05/BookOfAbstracts-2021.pdf.
  8. Tugay A., Gugnin O., Pulatova N., Zadorozhna L., Advanced morphology of VIPERS galaxies // Astronomy in Lviv University, Scientific conference to 360-th Anniversary of Lviv University, 250-th Anniversary of Astronomical observatory, and 25-th Anniversary of Astrophysics Department, September 14-17, 2021, Book of Abstracts. – 2021. – P. 88. https://astro.lnu.edu.ua/seminars/konferentsiji.
  9. Tugay A., Shevchenko S., Zadorozhna L. Topology of large scale structure of the Universe // 21-th Gamow International Astronomical Conference-School “Astronomy and beyond: Astrophysics, Cosmology and Gravitation, High Energy Physics, Astroparticle Physics, Radioastronomy and Astrobiology“, Odessa, Ukraine, August 15-21, 2021, Book of Abstracts. – 2021. – P. 9. http://gamow.odessa.ua/wp-content/uploads/2021/08/gamow-abstracts-2021.pdf.