Course Unit Page

Academic Year 2021/2022

Learning outcomes

At the end of the course, the student will have a good knowledge of the observational and physical properties of Active Galaxies in the various bands of the electromagnetic spectrum and their cosmic evolution. The first black hole in the Universe will be discussed along with their growth history and active phases. Knowledge of the strict link between the accretion processes of supermassive black holes at the center of galaxies and star-formation activity, in the so-called co-evolution scenario involving feedback processes, will also be acquired by students.

Course contents

Main topics: AGN physics and classification - AGN evolution - The first AGN in the Universe. AGN feedback.

  • Introduction to the course.
  • Brief historical perspective on AGN.
  • Pills on radiative transfer and on thermal and non-thermal processes.
  • AGN classification and unification model.
  • AGN Broad-band emission: observations, physical processes, and models.
  • On the nature of obscuration in AGN: torus vs. host galaxy. Photometric and spectroscopic selection techniques of obscured AGN.
  • The black hole paradigm. Radiatively efficient (Shakura-Sunyaev) accretion discs vs. ADAF solutions. Slim discs and their potential application to growing BHs.
  • A close look at the innermost regions of AGN: EHT and GRAVITY results.
  • The Galactic Center: SgrA* and its accretion history up the recent flares. The Galactic Plane: Fermi bubbles and X-ray chimneys.
  • AGN-galaxy co-evolution models at high redshift vs. AGN unification model.
  • Formation and evolution of AGN. X-ray surveys and the cosmic X-ray background. The Soltan argument.
  • The realm of high-redshift AGN and theories on seed black holes.
  • Jetted vs. not-jetted AGN. Emission processes, observational features, spectral energy distributions, and blazar sequence. Prospects for the Cerenkov Telescope Array.
  • BH masses from reverberation studies and scaling relations. 
  • Feedback (radiative/mechanic) from AGN. The impact of winds and outflows on small and large scales in setting the M-sigma relation. Recent multi-wavelength studies.
  • The role of mergers in triggering nuclear activity. The quest for dual/binary AGN in the era of gravitational waves. 



  • Hale Bradt: "Astrophysics Processes: The Physics Of Astronomical Phenomena", Cambridge University Press
  • George B. Rybicky, Alan P. Lightman: "Radiative Processes in Astrophysics", Wiley
  • Gabriele Ghisellini: "Radiative processes in high energy astrophysics", Springer, Lecture Notes in Physics 873
  • Bradley M. Peterson: "An introduction to Active Galactic Nuclei", Cambridge University Press
  • J. Frank, A. King & D. Raine: "Accretion Power in Astrophysics", Cambridge University Press
  • Frederick D. Seward, Philip A. Charles: "Exploring the X-ray Universe", Cambridge University Press
  • Hagai Netzer: "The Physics and Evolution of Active Galactic Nuclei", Cambridge University Press
  • Volker Beckmann, Chris Shrader: "Active Galactic Nuclei", Wiley-VCH
  • Haardt F., Gorini V., Moschella U., Treves A., Colpi M.:
    "Astrophysical Black Holes", Springer, Lecture Notes in Physics, 905
  • Falanga M., Belloni T., Casella P., Gilfanov M., Jonker P., King A.: "The Physics of Accretion onto Black Holes", Springer, Space Sciences Series of ISSI


(Review) Articles

  • B. Peterson: "The central black hole and relationships with the host galaxy", New Astronomy Reviews, 52, 240 (2008)
  • A. King: "Disc accretion in active galactic nuclei",New Astronomy Reviews, 52, 253 (2008)
  • S. Bianchi, R. Maiolino, G. Risaliti:"AGN Obscuration and the Unified Model", Advances in Astronomy, Vol. 2012, id. 782030 (arXiv:1201.2119)
  • A. Merloni:"Observing Supermassive Black Holes Across Cosmic Time: From Phenomenology to Physics", Astrophysical Black Holes, Lecture Notes in Physics, Springer, Vol. 905, p.101 (2015; arXiv:1505.04940)
  • M. Middleton: "Black hole spin: theory and observation", Astrophysics of Black Holes, Astrophysics and Space Science Library, Springer, Vol. 440, p.99 (2016, arXiv:1507.06153)
  • C. Tadhunter: "An introduction to active galactic nuclei: Classification and unification", New Astronomy Reviews, 52, 227 (2008)
  • H. Netzer: "Revisiting the Unified Model of Active Galactic Nuclei", ARA&A, 53, 365 (2015)
  • P. Padovani et al.:"Active galactic nuclei: what's in a name?", Astron. Astrophys. Rev., 25, 2 (2017)
  • M. Elitzur: "The toroidal obscuration of active galactic nuclei", New Astronomy Reviews, 52, 274 (2008)
  • C. R. Almeida, C. Ricci: "Nuclear obscuration in active galactic nuclei", Nature Astronomy 1, 679 (2017)
  • R.C. Hyckox, D.M. Alexander:"Obscured Active Galactic Nuclei", ARA&A, 56, 625 (2018)
  • M. Suganuma et al.: "Reverberation measurements in the inner radius of the dust torus in nearby Seyfert 1 galaxies", ApJ, 639, 46 (2006)
  • N.I. Shakura, R.A. Sunyaev: "Black Holes in Binary Systems. Observational appearance", A&A, 24, 337 (1973)
  • F. Yuan, R. Narayan: "Hot Accretion Flows Around Black Holes", ARA&A, 52, 529 (2014)
  • The Event Horizon Telescope Collaboration: "First M87 Event Horizon Telescope results. I. The shadow of the supermassive black hole", ApJ, 875, L1 (2019)
  • GRAVITY Collaboration: "Spatially resolved rotation of the broad-line region of a quasar at sub-parsec scale", Nature, 563, 657 (2018)
  • R. Genzel, F. Eisenhauser, S. Gillessen: "The Galactic Center massive black hole and nuclear star cluster", Reviews of modern physics, 82 (2010)
  • M.R. Morris, L. Meyer, A.M. Ghez: "Galactic Center research: manifestations of the central black hole", Research Astronomy Astrophysics, 12, 995 (2012)
  • G. Ponti, M.R. Morris, R. Terrier, A. Goldwurn:"Traces of past activity in the Galactic Center", arXiv:1210.3034 (2012)
  • W.N. Brandt, D.M. Alexander: "Cosmic X-ray surveys of distant active galaxies. The demographics, physics and ecology of growing supermassive black holes", Astron. Astrophys. Rev., 23, 1 (2015)
  • W.N. Brandt, D.M. Alexander: "Supermassive black-hole growth over cosmic time: Active galaxy demography, physics, and ecology from Chandra surveys", Publications of the National Academy of Science, 107, 16, p.7184 (2010)
  • K. Inayoshi, E. Visbal, Z. Haiman: "The Assembly of the First Black Holes", ARA&A, 58, 27 (2020)
  • R. Blandford, D. Meier, A. Readhead: "Relativistic jets from Active Galactic Nuclei", ARA&A, 57, 467 (2019)
  • A. Tchekhovskoy, J.C. McKinney, R. Narayan: "General relativistic modeling of magnetized jets from accreting black holes", Astronomy at High Angular Resolution 2011, Journal of Physics, Conf. Series 372 (2012)
  • M.J. Hardcastle, J.H. Croston: "Radio galaxies and feedback from AGN jets", New Astronomy Reviews, 88, 101539 (2020)
  • P.N. Best, T.H. Heckman: "On the fundamental dichotomy in the local radio-AGN population: accretion, evolution and host galaxy properties", MNRAS, 421, 1569 (2012)
  • D.E. Harris, H. Krawczynski: "X-ray emission from extragalactic jets", ARA&A, 44, 463 (2006)
  • B.M. Peterson: "Toward precision measurement of central black hole masses", proceedings IAU Symposium 267 (2010)
  • Y. Shen: "The mass of quasars", Bulletin of the Astronomical Society of India, 41, 61 (2013)
  • A. King & K. Pounds: "Powerful Outflows and Feedback from Active Galactic Nuclei", ARA&A, 53, 115 (2015)
  • A. King: "The supermassive black-hole - galaxy connection", Space Science Reviews, 183, 427
  • A. King: "The AGN-starburst connection, galactic superwinds, and Mbh-sigma", ApJ, 635, L121 (2005)
  • A. King: "Accretion and outflow in active galaxies", proceedings of IAU Symposium 267, 273 (2010)
  • A.C. Fabian: "Observational evidence of active galactic nuclei feedback", ARA&A, 50, 455 (2012)
  • C.M. Harrison: "Impact of supermassive black hole growth on star formation", Nature Astronomy, 1, 0165, arXiv:1703.06889 (2017)
  • C.M. Harrison et al.: "AGN outflows and feedback twenty years on", Nature Astronomy 2, 198, arXiv:1802.10306 (2018)
  • C. Cicone et al.: "Massive molecular outflows and evidence for AGN feedback from CO observations", A&A, 562, A21 (2014)
  • R. Morganti: "The many routes to AGN Feedback", Frontiers in Astronomy and Space Sciences, 4, 42 (2017)

Teaching methods

During lessons, carried out mostly using powerpoint presentations, some of the most interesting topics of modern astrophysics, in particular those related to AGN and SMBHs, will be discussed. Students are encouraged to go deeply into the topics faced in the course through careful reading of suggested-book chapters and of recent - mostly review - publications to have the state-of-the-art view related to the scientific topics of the course.

Assessment methods

Students' knowledge in the field of Active Galaxies will be based on an oral exam, starting with a topic chosen by the student, followed by questions on topics covered during the course. The student is required to link, in the most appropriate way, the various topics discussed during the course, and to be able to discuss in a critical way the main topics and open issues in modern astrophysics in the field of Active Galaxies and Super-Massive Black Holes. Besides, the student should show skiils in deriving physical quantities.

Teaching tools

Powerpoint presentations (available on the personal webpage and at IoL) and dashboard.

Office hours

See the website of Cristian Vignali