Archaeology of active galaxies across the electromagnetic spectrum

Abstract

Analytical and numerical galaxy-formation models indicate that active galactic nuclei (AGNs) likely play a prominent role in the formation and evolution of galaxies. However, quantifying this effect requires knowledge of how the nuclear activity proceeds throughout the life of a galaxy, whether it alternates with periods of quiescence and, if so, on what timescales these cycles occur. This topic has attracted growing interest, but making progress remains a challenging task. For optical and radio AGNs, a variety of techniques are used to perform a kind of ‘archaeology’ that traces the signatures of past nuclear activity. Here we summarize recent findings regarding the lifecycle of an AGN from optical and radio observations. The limited picture we have so far suggests that these cycles can range from long periods of 107–108 yr to shorter periods of 104–105 yr, even reaching extreme events on timescales of just a few years. Together with simulations, observational results regarding the multiple cycles of AGN activity help to create a complete picture of the AGN lifecycle.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Fig. 1: The prototypical example of ‘light echo’ and a proposed lifecycle.
Fig. 2: The duty cycle of activity and quiescence predicted from simulations of chaotic cold accretion.
Fig. 3: Model of integrated radio spectra showing how a power-law radio spectrum is modified by the ageing of the source and the switching off of the central AGN.
Fig. 4: Example of an AGN remnant (B2 0924+30) discovered thanks to the morphology of its radio emission90: all possible signatures of ongoing activity (core, jets and hot spots) are absent, and only diffuse, low-surface-brightness emission is detected.
Fig. 5: Radio galaxy B0925+420, showing three phases of activity.
Fig. 6: LOFAR image (one pointing) centred on the Boötes area87.

Image  W. Williams / R. van Weeren / H. Röttgering / D. Hoang.

Fig. 7: A serendipitously discovered AGN remnant100 in a LOFAR field with properties rarely seen before.
Fig. 8: Two views of the LOFAR radio telescope.

References

  1. 1.

    Di Matteo, T., Springel, V. & Hernquist, L. Energy input from quasars regulates the growth and activity of black holes and their host galaxies. Nature 433, 604–607 (2005).

    ADS  Article  Google Scholar 

  2. 2.

    Schaye, J. et al. The EAGLE project: Simulating the evolution and assembly of galaxies and their environments. Mon. Not. R. Astron. Soc 446, 521–554 (2015).

    ADS  Article  Google Scholar 

  3. 3.

    Sijacki, D. et al. The Illustris simulation: The evolving population of black holes across cosmic time. Mon. Not. R. Astron. Soc 452, 575–596 (2015).

    ADS  Article  Google Scholar 

  4. 4.

    McNamara, B. R. & Nulsen, P. E. J. Mechanical feedback from active galactic nuclei in galaxies, groups and clusters. New J. Phys. 14, 055023 (2012).

    ADS  Article  Google Scholar 

  5. 5.

    Fabian, A. C. Observational evidence of active galactic nuclei feedback. Annu. Rev. Astron. Astrophys. 50, 455–489 (2012).

    ADS  Article  Google Scholar 

  6. 6.

    Cicone, C. et al. Massive molecular outflows and evidence for AGN feedback from CO observations. Astron. Astrophys. 562, A21 (2014).

    Article  Google Scholar 

  7. 7.

    Morganti, R., Tadhunter, C. N. & Oosterloo, T. A. Fast neutral outflows in powerful radio galaxies: A major source of feedback in massive galaxies. Astron. Astrophys. 444, L9–L13 (2005).

    ADS  Article  Google Scholar 

  8. 8.

    Tombesi, F. et al. Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy. Nature 519, 436–438 (2015).

    ADS  Article  Google Scholar 

  9. 9.

    Woltjer, L. Emission nuclei in galaxies. Astrophys. J. 130, 38–44 (1959).

    ADS  MathSciNet  Article  Google Scholar 

  10. 10.

    Marconi, A. et al. Local supermassive black holes, relics of active galactic nuclei and the X-ray background. Mon. Not. R. Astron. Soc 351, 169–185 (2004).

    ADS  Article  Google Scholar 

  11. 11.

    Best, P. N. et al. The host galaxies of radio-loud active galactic nuclei: Mass dependences, gas cooling and active galactic nuclei feedback. Mon. Not. R. Astron. Soc 362, 25–40 (2005).

    ADS  Article  Google Scholar 

  12. 12.

    Saikia, D. J. & Jamrozy, M. Recurrent activity in active galactic nuclei. Bull. Astron. Soc. India 37, 63–89 (2009).

    ADS  Google Scholar 

  13. 13.

    Hogan, M. T. et al. High radio-frequency properties and variability of brightest cluster galaxies. Mon. Not. R. Astron. Soc 453, 1223–1240 (2015).

    ADS  Article  Google Scholar 

  14. 14.

    Heckman, T. M. & Best, P. N. The coevolution of galaxies and supermassive black holes: Insights from surveys of the contemporary universe. Annu. Rev. Astron. Astrophys. 52, 589–660 (2014).

    ADS  Article  Google Scholar 

  15. 15.

    Hardcastle, M. J., Evans, D. A. & Croston, J. H. Hot and cold gas accretion and feedback in radio-loud active galaxies. Mon. Not. R. Astron. Soc 376, 1849–1856 (2007).

    ADS  Article  Google Scholar 

  16. 16.

    Harrison, C. M. Impact of supermassive black hole growth on star formation. Nat. Astron. 1, 0165 (2017).

  17. 17.

    Heckman, T. M. et al. Galaxy collisions and mergers — The genesis of very powerful radio sources? Astrophys. J. 311, 526–547 (1986).

    ADS  Article  Google Scholar 

  18. 18.

    Hopkins, P. F. et al. The relation between quasar and merging galaxy luminosity functions and the merger-driven star formation history of the universe. Astrophys. J. 652, 864–888 (2006).

    ADS  Article  Google Scholar 

  19. 19.

    Ramos Almeida, C. et al. Are luminous radio-loud active galactic nuclei triggered by galaxy interactions? Mon. Not. R. Astron. Soc 419, 687–705 (2012).

    ADS  Article  Google Scholar 

  20. 20.

    Gaspari, M., Temi, P. & Brighenti, F. Raining on black holes and massive galaxies: The top-down multiphase condensation model. Mon. Not. R. Astron. Soc 466, 677–704 (2017).

    ADS  Article  Google Scholar 

  21. 21.

    Gaspari, M., Ruszkowski, M. & Oh, S. P. Chaotic cold accretion onto black holes. Mon. Not. R. Astron. Soc. 432, 3401–3422 (2013).

    ADS  Article  Google Scholar 

  22. 22.

    Ciotti, L., Ostriker, J. P. & Proga, D. Feedback from central black holes in elliptical galaxies. III. Models with both radiative and mechanical feedback. Astrophys. J 717, 708–723 (2010).

    ADS  Article  Google Scholar 

  23. 23.

    Ciotti, L., Pellegrini, S., Negri, A. & Ostriker, J. P. The effect of the AGN feedback on the interstellar medium of early-type galaxies: 2D hydrodynamical simulations of the low-rotation case. Astrophys. J. 835, 15 (2017).

    ADS  Article  Google Scholar 

  24. 24.

    van Haarlem, M. P. et al. LOFAR: The LOw-Frequency ARray. Astron. Astrophys. 556, A2 (2013).

    Article  Google Scholar 

  25. 25.

    Soltan, A. Masses of quasars. Mon. Not. R. Astron. Soc 200, 115–122 (1982).

    ADS  Article  Google Scholar 

  26. 26.

    Yu, Q. & Tremaine, S. Observational constraints on growth of massive black holes. Mon. Not. R. Astron. Soc 335, 965–976 (2002).

    ADS  Article  Google Scholar 

  27. 27.

    Lintott, C. J. et al. Galaxy Zoo: ‘Hanny’s Voorwerp’, a quasar light echo? Mon. Not. R. Astron. Soc 399, 129–140 (2009).

    ADS  Article  Google Scholar 

  28. 28.

    Józsa, G. I. G. et al. Revealing Hanny’s Voorwerp: Radio observations of IC 2497. Astron. Astrophys. 500, L33–L36 (2009).

    ADS  Article  Google Scholar 

  29. 29.

    Lintott, C. J. et al. Galaxy Zoo: Morphologies derived from visual inspection of galaxies from the Sloan Digital Sky Survey. Mon. Not. R. Astron. Soc. 389, 1179–1189 (2008).

    ADS  Article  Google Scholar 

  30. 30.

    Keel, W. C. et al. The Galaxy Zoo survey for giant AGN-ionized clouds: Past and present black hole accretion events. Mon. Not. R. Astron. Soc 420, 878–900 (2012).

    ADS  Article  Google Scholar 

  31. 31.

    Schawinski, K., Koss, M., Berney, S. & Sartori, L. F. Active galactic nuclei flicker: An observational estimate of the duration of black hole growth phases of ~105 yr. Mon. Not. R. Astron. Soc 451, 2517–2523 (2015).

    ADS  Article  Google Scholar 

  32. 32.

    Sun, A.-L., Greene, J. E. & Zakamska, N. L. Sizes and kinematics of extended narrow-line regions in luminous obscured AGN selected by broadband images. Astrophys. J. 835, 222 (2017).

    ADS  Article  Google Scholar 

  33. 33.

    Husemann, B., Wisotzki, L., Sánchez, S. F. & Jahnke, K. The properties of the extended warm ionised gas around low-redshift QSOs and the lack of extended high-velocity outflows. Astron. Astrophys. 549, A43 (2013).

    ADS  Article  Google Scholar 

  34. 34.

    Storchi-Bergmann, T., Baldwin, J. A. & Wilson, A. S. Double-peaked broad line emission from the LINER nucleus of NGC 1097. Astrophys. J. 410, L11–L14 (1993).

    ADS  Article  Google Scholar 

  35. 35.

    Lamassa, S. Astronomy: A black hole changes its feeding habits. Nature 540, 48–49 (2016).

    ADS  Article  Google Scholar 

  36. 36.

    McElroy, R. E. et al. The Close AGN Reference Survey (CARS). Mrk 1018 returns to the shadows after 30 years as a Seyfert 1. Astron. Astrophys. 593, L8 (2016).

    ADS  Article  Google Scholar 

  37. 37.

    Koay, J. Y., Vestergaard, M., Casasola, V., Lawther, D. & Peterson, B. M. ALMA probes the molecular gas reservoirs in the changing-look Seyfert galaxy Mrk 590. Mon. Not. R. Astron. Soc 455, 2745–2764 (2016).

    ADS  Article  Google Scholar 

  38. 38.

    LaMassa, S. M. et al. The discovery of the first ‘changing look’ quasar: New insights into the physics and phenomenology of active galactic nucleus. Astrophys. J. 800, 144 (2015).

    ADS  Article  Google Scholar 

  39. 39.

    Runnoe, J. C. et al. Now you see it, now you don’t: The disappearing central engine of the quasar J1011+5442. Mon. Not. R. Astron. Soc 455, 1691–1701 (2016).

    ADS  Article  Google Scholar 

  40. 40.

    Ruan, J. J. et al. Toward an understanding of changing-look quasars: An archival spectroscopic search in SDSS. Astrophys. J. 826, 188 (2016).

    ADS  Article  Google Scholar 

  41. 41.

    Gezari, S. et al. iPTF discovery of the rapid ‘turn on’ of a luminous quasar. Astrophys. J. 835, 144–155 (2017).

    ADS  Article  Google Scholar 

  42. 42.

    Kochanek, C. S. Tidal disruption event demographics. Mon. Not. R. Astron. Soc 461, 371–384 (2016).

    ADS  Article  Google Scholar 

  43. 43.

    Merloni, A. et al. A tidal disruption flare in a massive galaxy? Implications for the fuelling mechanisms of nuclear black holes. Mon. Not. R. Astron. Soc 452, 69–87 (2015).

    ADS  Article  Google Scholar 

  44. 44.

    Law, N. M. et al. The Palomar Transient Factory: System overview, performance, and first results. Publ. Astron. Soc. Pac. 121, 1395–1408 (2009).

    ADS  Article  Google Scholar 

  45. 45.

    Chambers, K. C. et al. The Pan-STARRS1 Surveys. Preprint at https://arxiv.org/abs/1612.05560 (2016).

  46. 46.

    Ivezic, Z. et al. LSST: From science drivers to reference design and anticipated data products. Preprint at https://arxiv.org/abs/0805.2366 (2008).

  47. 47.

    Novak, G. S., Ostriker, J. P. & Ciotti, L. Feedback from central black holes in elliptical galaxies: Two-dimensional models compared to one-dimensional models. Astrophys. J. 737, 26 (2011).

    ADS  Article  Google Scholar 

  48. 48.

    Tremblay, G. R. et al. Cold, clumpy accretion onto an active supermassive black hole. Nature 534, 218–221 (2016).

    ADS  Article  Google Scholar 

  49. 49.

    Maccagni, F. M. et al. The warm molecular hydrogen of PKS B1718–649 feeding a newly born radio AGN. Astron. Astrophys. 588, A46 (2016).

    Article  Google Scholar 

  50. 50.

    Wagner, A. Y., Bicknell, G. V. & Umemura, M. Driving outflows with relativistic jets and the dependence of active galactic nucleus feedback efficiency on interstellar medium inhomogeneity. Astrophys. J. 757, 136 (2012).

    ADS  Article  Google Scholar 

  51. 51.

    Shabala, S. S., Ash, S., Alexander, P. & Riley, J. M. The duty cycle of local radio galaxies. Mon. Not. R. Astron. Soc 388, 625–637 (2008).

    ADS  Article  Google Scholar 

  52. 52.

    Vantyghem, A. N. et al. Cycling of the powerful AGN in MS 0735.6+7421 and the duty cycle of radio AGN in clusters. Mon. Not. R. Astron. Soc. 442, 3192–3205 (2014).

    ADS  Article  Google Scholar 

  53. 53.

    Kellermann, K. I. The spectra of non-thermal radio sources. Astrophys. J. 140, 969–991 (1964).

    ADS  Article  Google Scholar 

  54. 54.

    Pacholczyk, A. G. Radio astrophysics: Nonthermal processes in galactic and extragalactic sources. Phys. Today 24, 57 (1970).

    Article  Google Scholar 

  55. 55.

    Kardashev, N. S. Nonstationarity of spectra of young sources of nonthermal radio emission. Soviet Astron 6, 317–327 (1962).

    ADS  Google Scholar 

  56. 56.

    Jaffe, W. J. & Perola, G. C. Dynamical models of tailed radio sources in clusters of galaxies. Astron. Astrophys. 26, 423–435 (1973).

    ADS  Google Scholar 

  57. 57.

    Komissarov, S. S. & Gubanov, A. G. Relic radio galaxies: Evolution of synchrotron spectrum. Astron. Astrophys. 285, 27–43 (1994).

    ADS  Google Scholar 

  58. 58.

    Blundell, K. M. & Rawlings, S. The spectra and energies of classical double radio lobes. Astrophys. J 119, 1111–1122 (2000).

    ADS  Google Scholar 

  59. 59.

    Eilek, J. A. How radio sources stay young: Spectral aging revisited. Proc. Energy Transport in Radio Galaxies and Quasars 100, 281–286 (1996).

    ADS  Google Scholar 

  60. 60.

    Katz-Stone, D. M., Rudnick, L. & Anderson, M. C. Determining the shape of spectra in extended radio sources. Astrophys. J. 407, 549–555 (1993).

    ADS  Article  Google Scholar 

  61. 61.

    Tribble, P. C. Radio spectral ageing in a random magnetic field. Mon. Not. R. Astron. Soc 261, 57–62 (1993).

    ADS  Article  Google Scholar 

  62. 62.

    Hardcastle, M. J. Synchrotron and inverse-Compton emission from radio galaxies with non-uniform magnetic field and electron distributions. Mon. Not. R. Astron. Soc 433, 3364–3372 (2013).

    ADS  Article  Google Scholar 

  63. 63.

    Harwood, J. J., Hardcastle, M. J., Croston, J. H. & Goodger, J. L. Spectral ageing in the lobes of FR-II radio galaxies: New methods of analysis for broad-band radio data. Mon. Not. R. Astron. Soc 435, 3353–3375 (2013).

    ADS  Article  Google Scholar 

  64. 64.

    Harwood, J. J. et al. FR II radio galaxies at low frequencies. I. Morphology, magnetic field strength and energetics. Mon. Not. R. Astron. Soc 458, 4443–4455 (2016).

    ADS  Article  Google Scholar 

  65. 65.

    Alexander, P. & Leahy, J. P. Ageing and speeds in a representative sample of 21 classical double radio sources. Mon. Not. R. Astron. Soc 225, 1–26 (1987).

    ADS  Article  Google Scholar 

  66. 66.

    Parma, P. et al. Radiative ages in a representative sample of low luminosity radio galaxies. Astron. Astrophys. 344, 7–16 (1999).

    ADS  Google Scholar 

  67. 67.

    Liu, R., Pooley, G. & Riley, J. M. Spectral ageing in a sample of 14 high-luminosity double radio sources. Mon. Not. R. Astron. Soc 257, 545–571 (1992).

    ADS  Article  Google Scholar 

  68. 68.

    O’Dea, C. P. The compact steep-spectrum and gigahertz peaked-spectrum radio sources. Publ. Astron. Soc. Pac. 110, 493–532 (1998).

    ADS  Article  Google Scholar 

  69. 69.

    Snellen, I. A. G. et al. On the evolution of young radio-loud AGN. Mon. Not. R. Astron. Soc 319, 445–456 (2000).

    ADS  Article  Google Scholar 

  70. 70.

    Orienti, M. Radio properties of compact steep spectrum and GHz-peaked spectrum radio sources. Astron. Nachrichten 337, 9–17 (2016).

    ADS  Article  Google Scholar 

  71. 71.

    Fanti, C. et al. Are compact steep-spectrum sources young? Astron. Astrophys. 302, 317 (1995).

    ADS  Google Scholar 

  72. 72.

    Bicknell, G. V., Dopita, M. A. & O’Dea, C. P. O. Unification of the radio and optical properties of gigahertz peak spectrum and compact steep-spectrum radio sources. Astrophys. J. 485, 112–124 (1997).

    ADS  Article  Google Scholar 

  73. 73.

    Tingay, S. J. & de Kool, M. An investigation of synchrotron self-absorption and free-free absorption models in explanation of the gigahertz-peaked spectrum of PKS 1718–649. Astron. J. 126, 723–733 (2003).

    ADS  Article  Google Scholar 

  74. 74.

    Owsianik, I., Conway, J. E. & Polatidis, A. G. Renewed radio activity of age 370 years in the extragalactic source 0108+388. Astron. Astrophys. 336, L37–L40 (1998).

    ADS  Google Scholar 

  75. 75.

    Kunert-Bajraszewska, M., Marecki, A., Thomasson, P. & Spencer, R. E. FIRST-based survey of compact steep spectrum sources. II. MERLIN and VLA observations of medium-sized symmetric objects. Astron. Astrophys 440, 93–105 (2005).

    ADS  Article  Google Scholar 

  76. 76.

    Orienti, M., Murgia, M. & Dallacasa, D. The last breath of the young gigahertz-peaked spectrum radio source PKS1518+047. Mon. Not. R. Astron. Soc 402, 1892–1898 (2010).

    ADS  Article  Google Scholar 

  77. 77.

    Callingham, J. R. et al. Broadband spectral modeling of the extreme gigahertz-peaked spectrum radio source PKS B0008–421. Astrophys. J. 809, 168 (2015).

    ADS  Article  Google Scholar 

  78. 78.

    Holt, J., Tadhunter, C. N. & Morganti, R. Fast outflows in compact radio sources: evidence for AGN-induced feedback in the early stages of radio source evolution. Mon. Not. R. Astron. Soc 387, 639–659 (2008).

    ADS  Article  Google Scholar 

  79. 79.

    Shabala, S. S. et al. Delayed triggering of radio active galactic nuclei in gas-rich minor mergers in the local Universe. Mon. Not. R. Astron. Soc 464, 4706–4720 (2017).

    ADS  Article  Google Scholar 

  80. 80.

    Stanghellini, C. et al. Extended emission around GPS radio sources. Astron. Astrophys. 443, 891–902 (2005).

    ADS  Article  Google Scholar 

  81. 81.

    Schoenmakers, A. P., de Bruyn, A. G., Röttgering, H. J. A. & van der Laan, H. Radio galaxies with a ‘double-double’ morphology — III. The case of B1834+620. Mon. Not. R. Astron. Soc 315, 395–406 (2000).

    ADS  Article  Google Scholar 

  82. 82.

    Brocksopp, C., Kaiser, C. R., Schoenmakers, A. P. & de Bruyn, A. G. Three episodes of jet activity in the Fanaroff–Riley type II radio galaxy B0925+420. Mon. Not. R. Astron. Soc 382, 1019–1028 (2007).

    ADS  Article  Google Scholar 

  83. 83.

    Konar, C., Hardcastle, M. J., Jamrozy, M. & Croston, J. H. Episodic radio galaxies J0116–4722 and J1158+2621: Can we constrain the quiescent phase of nuclear activity? Mon. Not. R. Astron. Soc 430, 2137–2153 (2013).

    ADS  Article  Google Scholar 

  84. 84.

    Konar, C. & Hardcastle, M. J. Particle acceleration and dynamics of double-double radio galaxies: Theory versus observations. Mon. Not. R. Astron. Soc 436, 1595–1614 (2013).

    ADS  Article  Google Scholar 

  85. 85.

    Orrù, E. et al. Wide-field LOFAR imaging of the field around the double-double radio galaxy B1834+620. A fresh view on a restarted AGN and doubeltjes. Astron. Astrophys. 584, A112 (2015).

    Article  Google Scholar 

  86. 86.

    Tingay, S. J. et al. The Murchison Widefield Array: The Square Kilometre Array precursor at low radio frequencies. Pub. Astron. Soc. Australia 30, 7 (2013).

    ADS  Article  Google Scholar 

  87. 87.

    Williams, W. L. et al. LOFAR 150-MHz observations of the Boötes field: Catalogue and source counts. Mon. Not. R. Astron. Soc 460, 2385–2412 (2016).

    ADS  Article  Google Scholar 

  88. 88.

    Hardcastle, M. J. et al. LOFAR/H-ATLAS: A deep low-frequency survey of the Herschel–ATLAS North Galactic Pole field. Mon. Not. R. Astron. Soc 462, 1910–1936 (2016).

    ADS  Article  Google Scholar 

  89. 89.

    Mahony, E. K. et al. The Lockman Hole project: LOFAR observations and spectral index properties of low-frequency radio sources. Mon. Not. R. Astron. Soc 463, 2997–3020 (2016).

    ADS  Article  Google Scholar 

  90. 90.

    Cordey, R. A. IC 2476 — A possible relic radio galaxy. Mon. Not. R. Astron. Soc 227, 695–700 (1987).

    ADS  Article  Google Scholar 

  91. 91.

    Parma, P. et al. In search of dying radio sources in the local universe. Astron. Astrophys. 470, 875–888 (2007).

    ADS  Article  Google Scholar 

  92. 92.

    Murgia, M. et al. Dying radio galaxies in clusters. Astron. Astrophys. 526, 148 (2011).

    Article  Google Scholar 

  93. 93.

    Giovannini, G., Feretti, L., Gregorini, L. & Parma, P. Radio nuclei in elliptical galaxies. Astron. Astrophys. 199, 73–84 (1988).

    ADS  Google Scholar 

  94. 94.

    Saripalli, L. et al. ATLBS extended source sample: The evolution in radio source morphology with flux density. Astrophys. J. Suppl. Ser. 199, 27 (2012).

    ADS  Article  Google Scholar 

  95. 95.

    van Weeren, R. J., Röttgering, H. J. A., Brüggen, M. & Cohen, A. A search for steep spectrum radio relics and halos with the GMRT. Astron. Astrophys. 508, 75–92 (2009).

    ADS  Article  Google Scholar 

  96. 96.

    Dwarakanath, K. S. & Kale, R. Relics of double radio sources. Astrophys. J. 698, L163–L168 (2009).

    ADS  Article  Google Scholar 

  97. 97.

    Brienza, M. et al. Search and modeling of remnant radio galaxies in the LOFAR Lockman Hole field. Preprint available at https://arxiv.org/abs/1708.01904 (2017).

  98. 98.

    Godfrey, L., Morganti, R. & Brienza, M. On the population of remnant FRII radio galaxies and implications for radio source dynamics. Preprint available at https://arxiv.org/abs/1706.05909 (2017).

  99. 99.

    Shulevski, A. et al. Radiative age mapping of the remnant radio galaxy B2 0924+30: The LOFAR perspective. Astron. Astrophys. 600, 65 (2017).

    Article  Google Scholar 

  100. 100.

    Brienza, M. et al. LOFAR discovery of a 700-kpc remnant radio galaxy at low redshift. Astron. Astrophys. 585, A29 (2016).

    Article  Google Scholar 

  101. 101.

    Kaiser, C. R. & Cotter, G. The death of FR II radio sources and their connection with radio relics. Mon. Not. R. Astron. Soc 336, 649–658 (2002).

    ADS  Article  Google Scholar 

  102. 102.

    Turner, R. J. & Shabala, S. S. Energetics and lifetimes of local radio active galactic nuclei. Astrophys. J. 806, 59 (2015).

    ADS  Article  Google Scholar 

  103. 103.

    Shimwell, T. W. et al. The LOFAR two-metre sky survey — I. Survey description and preliminary data release. Astron. Astrophys. 598, 104 (2017).

    Article  Google Scholar 

  104. 104.

    Banfield, J. K. et al. Radio Galaxy Zoo: Host galaxies and radio morphologies derived from visual inspection. Mon. Not. R. Astron. Soc 453, 2326–2340 (2015).

    ADS  Article  Google Scholar 

Download references

Acknowledgements

I would like to thank T. Oosterloo, M. Gaspari, L. Godfrey, M. Brienza, J. Harwood, A. Shulevski, L. Ciotti and the LOFAR Survey Team for help, comments and discussions. The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Advanced Grant RADIOLIFE-320745. LOFAR was designed and constructed by ASTRON and has facilities in several countries that are owned by various parties (each with their own funding sources), and that are collectively operated by the International LOFAR Telescope foundation under a joint scientific policy.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Raffaella Morganti.

Ethics declarations

Competing interests

The author declares no competing financial interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Morganti, R. Archaeology of active galaxies across the electromagnetic spectrum. Nat Astron 1, 39–48 (2017). https://doi.org/10.1038/s41550-017-0223-0

Download citation

Further reading

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing