Relativistic plasmas in AGN jets

From synchrotron radiation to γ-ray emission
  • Giovanni La Mura
  • Giovanni Busetto
  • Stefano Ciroi
  • Piero Rafanelli
  • Marco Berton
  • Enrico Congiu
  • Valentina Cracco
  • Michele Frezzato
Regular Article
Part of the following topical collections:
  1. Topical Issue: Physics of Ionized Gases (SPIG 2016)


Relativistic jets of plasma are a key ingredient of many types of Active Galactic Nuclei (AGN). Today we know that AGNs are powered by the accretion of interstellar material into the gravitational field of a Super Massive Black Hole, and that this process can release as much power as an entire galaxy the size of the Milky Way, from a region that is comparable to the Solar System in size. Depending on the properties of the central energy source, a large fraction of this power can be involved in the acceleration of magnetized plasmas at relativistic speeds, to form large-scale jets. The presence of jets affects the spectrum of AGNs through the emission of synchrotron radiation and Inverse Compton scattering of low energy photons, thus leading to a prominent non-thermal spectrum, sometimes extending from radio frequencies all the way up to γ-ray energies. Here we review some characteristic processes of radiation emission in AGN jets, which lead to the emission of photons in the radio, optical, X-ray and γ-ray bands, and we present the results of a spectroscopic campaign of optical counterparts. We discuss our observations and their connection with γ-ray properties in a scenario that traces the role of relativistic jets in different classes of AGNs, detected in both the local and the remote Universe.

Graphical abstract


  1. 1.
    R.E. Rothschild, R.F. Mushotzky, W.A. Baity, D.E. Gruber, J.L. Matteson, L.E. Peterson, Astrophys. J. 269, 423 (1983)ADSCrossRefGoogle Scholar
  2. 2.
    R.F. Mushotzky, Adv. Space Res. 3, 157 (1984)ADSCrossRefGoogle Scholar
  3. 3.
    T.J. Turner, K.A. Pounds, Mon. Not. R. Astr. Soc. 240, 833 (1989)ADSCrossRefGoogle Scholar
  4. 4.
    M. Elvis, B.J. Wilkes, J.C. McDowell, R.F. Green, J. Bechtold, S.P. Willner, M.S. Oey, E. Polomski, R. Cutri, Astrophys. J. Suppl. Ser. 95, 1 (1994)ADSCrossRefGoogle Scholar
  5. 5.
    L.C. Ho, Astrophys. J. 516, 672 (1999)ADSCrossRefGoogle Scholar
  6. 6.
    G.T. Richards, M. Lacy, L.J. Storrie-Lombardi, P.B. Hall, S.C. Gallagher, D.C. Hines, X. Fan, C. Papovich, D.E. Vanden Berk, G.B. Trammell, D.P. Schneider, M. Vestergaard, D.G. York, S. Jester, S.F. Anderson, T. Budavari, A.S. Szalay, Astrophys. J. Suppl. Ser. 166, 470 (2006)ADSCrossRefGoogle Scholar
  7. 7.
    Z. Shang, M.S. Brotherton, B.J. Wills, D. Wills, S.L. Cales, D.A. Dale, R.F. Green, J.C. Runnoe, R.S. Nemmen, S.C. Gallagher, R. Ganguly, D.C. Hines, B.J. Kelly, G.A. Kriss, J. Li, B. Tang, Y. Xie, Astrophys. J. Suppl. Ser. 196, 2 (2011)ADSCrossRefGoogle Scholar
  8. 8.
    C.M. Krawczyk, G.T. Richards, S.S. Mehta, M.S. Vogeley, S.C. Gallagher, K.M. Leighly, N.P. Ross, D.P. Schneider, Astrophys. J. Suppl. Ser. 206, 4 (2013)ADSCrossRefGoogle Scholar
  9. 9.
    R.V.E. Lovelace, Nature 262, 649 (1976)ADSCrossRefGoogle Scholar
  10. 10.
    R.D. Blandford, Mon. Not. R. Astr. Soc. 176, 465 (1976)ADSCrossRefGoogle Scholar
  11. 11.
    R.D. Blandford, R.L. Znajek, Mon. Not. R. Astr. Soc. 179, 433 (1977)ADSCrossRefGoogle Scholar
  12. 12.
    R.D. Blandford, D.G. Payne, Mon. Not. R. Astr. Soc. 199, 883 (1982)ADSCrossRefGoogle Scholar
  13. 13.
    R. Antonucci, Annu. Rev. Astron. Astr. 31, 473 (1993)ADSCrossRefGoogle Scholar
  14. 14.
    T.M. Heckman, P.N. Best, Annu. Rev. Astron. Astr. 52, 589 (2014)ADSCrossRefGoogle Scholar
  15. 15.
    A.Y.K.N. Oshlack, R.L. Webster, M.T. Whiting, Astrophys. J. 558, 5780 (2001)CrossRefGoogle Scholar
  16. 16.
    S.G. Jorstad, A.P. Marscher, M.L. Lister, A.M. Stirling, T.V. Cawthorne, W.K. Gear, J.L. Gómez, J.A. Stevens, P.S. Smith, J.R. Forster, E.I. Robson, Astron. J. 130, 1418 (2005)ADSCrossRefGoogle Scholar
  17. 17.
    W.B. Atwood et al., Astrophys. J. 697, 1071 (2009)ADSCrossRefGoogle Scholar
  18. 18.
    M. Ackermann et al., Astrophys. J. 810, 14 (2015)ADSCrossRefGoogle Scholar
  19. 19.
    H.D. Curtis, Publications of the Lick Observatory 13, 9 (1918)ADSGoogle Scholar
  20. 20.
    M. Boettcher, D.E. Harris, H. Krawczinski, Relativistic Jets from Active Galactic Nuclei (Wiley-VCH, Weinheim, Germany, 2012)Google Scholar
  21. 21.
    G.B. Rybicki, A.P. Lightman, Radiative Processes in Astrophysics (Wiley-VCH, Weinheim, Germany, 1991)Google Scholar
  22. 22.
    L. Foschini, M. Berton, A. Caccianiga, S. Ciroi, V. Cracco, B.M. Peterson, E. Angelakis, V. Braito, L. Fuhrmann, L. Gallo, D. Grupe, E. Järvelä, S. Kaufmann, S. Komossa, Y.Y. Kovalev, A. Lähteenmäki, M.M. Lisakov, M.L. Lister, S. Mathur, J.L. Richards, P. Romano, A. Sievers, G. Tagliaferri, J. Tammi, O. Tibolla, M. Tornikoski, S. Vercellone, G. La Mura, L. Maraschi, P. Rafanelli, A&A 575, 13 (2015)ADSCrossRefGoogle Scholar
  23. 23.
    M. Berton, A. Caccianiga, L. Foschini, B.M. Peterson, S. Mathur, G. Terreran, S. Ciroi, E. Congiu, V. Cracco, M. Frezzato, G. La Mura, P. Rafanelli, A&A 591, 98 (2016)ADSCrossRefGoogle Scholar
  24. 24.
    S.A. Smee, J.E. Gunn, A. Uomoto, N. Roe, D. Schlegel, C.M. Rockosi, M.A. Carr, F. Leger, K.S. Dawson, M.D. Olmstead, J. Brinkmann, R. Owen, R.H. Barkhouser, K. Honscheid, P. Harding, D. Long, R.H. Lupton, C. Loomis, et al., Astron. J. 146, 32 (2013)ADSCrossRefGoogle Scholar
  25. 25.
    S. Yao, Y. Weimin, Z. Hongyan, S. Komossa, J. Zhang, E. Qiao, B. Liu, Mon. Not. R. Astr. Soc. 454, 16 (2015)ADSCrossRefGoogle Scholar
  26. 26.
    F. Massaro, R. D’Abrusco, M. Ajello, J.E. Grindlay, H.A. Smith, Astrophys. J. 740, 48 (2011)ADSCrossRefGoogle Scholar
  27. 27.
    R. D’Abrusco, F. Massaro, M. Ajello, J.E. Grindlay, H.A. Smith, G. Tosti, Astrophys. J. 748, 68 (2012)ADSCrossRefGoogle Scholar
  28. 28.
    F. Massaro, R. D’Abrusco, G. Tosti, M. Ajello, D. Gasparrini, J.E. Grindlay, H.A. Smith, Astrophys. J. 750, 138 (2012)ADSCrossRefGoogle Scholar
  29. 29.
    D.G. York et al., Astron. J. 120, 1579 (2000)ADSCrossRefGoogle Scholar
  30. 30.
    F.D. Albareti, C. Allende Prieto, Almeida A. et al., Astrophys. J. Suppl. Ser. (submitted)Google Scholar
  31. 31.
    N. Álvarez Crespo, N. Masetti, F. Ricci, M. Landoni, V. Patiño-Álvarez, F. Massaro, R. D’Abrusco, A. Paggi, V. Chavushyan, E. Jiménez-Bailón, J. Torrealba, L. Latronico, F. La Franca, H.A. Smith, G. Tosti, Astron. J. 151, 32 (2016)ADSCrossRefGoogle Scholar
  32. 32.
    N. Álvarez Crespo, F. Massaro, D. Milisavljevic, M. Landoni, V. Chavushyan, V. Patiño-Álvarez, N. Masetti, E. Jiménez-Bailón, J. Strader, L. Chomiuk, H. Katagiri, M. Kagaya, C.C. Cheung, A. Paggi, R. D’Abrusco, F. Ricci, F. La Franca, H.A. Smith, G. Tosti, Astron. J. 151, 95 (2016)ADSCrossRefGoogle Scholar
  33. 33.
    N. Álvarez Crespo, F. Massaro, R. D’Abrusco, M. Landoni, N. Masetti, V. Chavushyan, E. Jiménez-Bailón, F. La Franca, D. Milisavljevic, A. Paggi, V. Patiño-Álvarez, F. Ricci, H.A. Smith, Astrophys. Space Sci. 361, 316 (2016)ADSCrossRefGoogle Scholar
  34. 34.
    F. Massaro, N. Álvarez Crespo, R. D’Abrusco, M. Landoni, N. Masetti, F. Ricci, D. Milisavljevic, A. Paggi, V. Chavushyan, E. Jiménez-Bailón, V. Patiño-Álvarez, J. Strader, L. Chomiuk, F. La Franca, H.A. Smith, G. Tosti, Astrophys. Space Sci. 361, 337 (2016)ADSCrossRefGoogle Scholar
  35. 35.
    G. Chiaro, D. Salvetti, La G. Mura, M. Giroletti, D.J. Thompson, D. Bastieri, Mon. Not. R. Astr. Soc. 462, 3180 (2016)ADSCrossRefGoogle Scholar
  36. 36.
    D.E. Osterbrock, G.J. Ferland, Astrophysics of Gaseous Nebulae and Active Galactic Nuclei - Second Edition (University Science Books, Sausalito, California, 2006)Google Scholar
  37. 37.
    F. Tavecchio, G. Ghisellini, G. Bonnoli, G. Ghirlanda, Mon. Not. R. Astr. Soc. 405, 94 (2010)ADSCrossRefGoogle Scholar
  38. 38.
    J. Poutanen, B. Stern, Astrophys. J. Lett. 717, L118 (2010)ADSCrossRefGoogle Scholar
  39. 39.
    M. Sikora, R. Moderski, G.M. Madejski, Astrophys. J. 675, 71 (2008)ADSCrossRefGoogle Scholar
  40. 40.
    S.G. Jorstad, A.P. Marscher, V.M. Larionov, I. Agudo, P.S. Smith, M. Gurwell, A. Lähteenmäki, M. Tornikoski, A. Markowitz et al., Astrophys. J. 715, 362 (2010)ADSCrossRefGoogle Scholar
  41. 41.
    J. Léon-Tavares, V. Chavushyan, V. Patiño-Álvarez, E. Valtaoja, T.G. Arshakian, L.Č. Popović, M. Tornikoski, A. Lobanov, A. Carramiñana, L. Carrasco, A. Lähteenmäki, Astrophys. J. Lett. 763, L36 (2013)ADSCrossRefGoogle Scholar
  42. 42.
    J.C. Isler, C.M. Urry, P. Coppi, C. Bailyn, R. Chatterjee, G. Fossati, E.W. Bonning, L. Maraschi, M. Buxton, Astrophys. J. 779, 100 (2013)ADSCrossRefGoogle Scholar
  43. 43.
    P. Abolmasov, J. Poutanen, Mon. Not. R. Astr. Soc. 464, 152 (2017)ADSCrossRefGoogle Scholar
  44. 44.
    P.M.W. Kalberla, W.B. Burton, D. Hartmann, E.M. Arnal, E. Bajaja, R. Morras, W.G.L. Pöppel, A&A 440, 775 (2005)ADSCrossRefGoogle Scholar
  45. 45.
    J.J. Condon, W.D. Cotton, E.W. Greisen, Q.F. Yin, R.A. Perley, G.B. Taylor, J.J. Broderick, Astron. J. 115, 1693 (1998)ADSCrossRefGoogle Scholar
  46. 46.
    T. Boller, M.J. Freyberg, J. Trümper, F. Haberl, W. Voges, K. Nandra, A&A 588, 103 (2016)ADSCrossRefGoogle Scholar
  47. 47.
    F.J. Lockman, K. Jahoda, D. McCammon, Astrophys. J. 302, 432 (1986)ADSCrossRefGoogle Scholar
  48. 48.
    J.M. Dickey, F.J. Lockman, Annu. Rev. Astron. Astr. 28, 215 (1990)ADSCrossRefGoogle Scholar
  49. 49.
    G. La Mura, G. Chiaro, S. Ciroi, P. Rafanelli, D. Salvetti, M. Berton, V. Cracco, J. Astrophys. Astron. 36, 447 (2015)ADSGoogle Scholar
  50. 50.
    R. Mukherjee, ATel #9599 (2016)Google Scholar
  51. 51.
    J.D. Finke, Astrophys. J. 830, 94 (2016)ADSCrossRefGoogle Scholar

Copyright information

© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  1. 1.Dipartimento di Fisica e Astronomia – Università di PadovaPadovaItaly

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