The Cosmological Evolution of Active Galaxies

  • James S. Dunlop
Part of the Astrophysics and Space Science Library book series (ASSL, volume 187)


Our current knowledge of the cosmological evolution of radio galaxies, radio loud quasars, optically selected QSOs, X-ray selected QSOs and starburst galaxies is reviewed and summarised. Between z = 0 and z = 2 the level of evolution of these active galaxies is now reasonably well established; the luminosity functions of all five classes of object appear to display remarkably similar power-law luminosity evolution of the form L(z) ∞ (1 + z)3. However, the exact nature of this evolution remains uncertain and, in particular, the results of several recent surveys are now casting some doubt on the simple, ‘established’ picture of pure luminosity evolution for the QSO optical luminosity function. At z > 2 it is clear that this strong evolution in the luminosity functions of radio galaxies, radio quasars and optical QSOs must slow down and effectively cease. However, the evidence for a high-redshift reduction in their comoving density remains tantalising. For optically selected QSOs there is some evidence for a redshift cutoff at ‘intermediate’ luminosities (-27 < M B < -26), but the space density of very luminous QSOs with M B < -27 seems to remain unchanged between z = 2 and z = 4. The radio population may display qualitatively similar behaviour; there is evidence for a high-redshift ‘cutoff in the number of radio galaxies and quasars with P 2.7GHz≃ 1026 WHz-1sr-1, but somewhat less clear evidence for any decline in the space density of sources with P 2.7GHz≃ 1027 WHz-1sr-1. The significance of these results, and the prospects for improving their robustness are briefly discussed.

Key words

cosmology: observations quasars: general galaxies: active galaxies: formation. 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Barthel, P.D., 1989, ApJ, 336, 606.Google Scholar
  2. Boyle, B.J., 1992. In: Cosmology & Particle Physics, Texas-ESO/CERNS ymp. on Relativistic Astrophysics, eds. Barrow, J., Mestel, L. & Thomas, P., Ann. N.Y. Acad. of Sci., 647, 14.Google Scholar
  3. Boyle, B.J., 1993. In: The Evolution of Galaxies and their environment, Proc. 3rd Teton Summer School, eds. Schull, M. & Thronson, H., in press.Google Scholar
  4. Boyle, B.J., Shanks, T. & Peterson, B.A., 1988. MNRAS, 238, 957.Google Scholar
  5. Boyle, B.J., Jones, L.R., Shanks, T., Marano, B., Zitelli, V. & Zamorani, G., 1991. In The Space Distribution of Quasars, ASP Conf Ser. No. 27, p. 191, ed. Crampton, D., ASP.Google Scholar
  6. Boyle, B.J., Griffiths, R.E., Shanks, T., Stewart, G.C. & Georgantopoulos, I., 1991 MNRAS, 260, 49.ADSGoogle Scholar
  7. Broadhurst, T.J., Ellis, R.S. & Glazebrook, K., 1992. Nature, 355, 55.ADSCrossRefGoogle Scholar
  8. Carlberg, R.G., 1990. ApJ, 350, 505.ADSCrossRefGoogle Scholar
  9. Dunlop, J.S. & Peacock, J.A., 1990. MNRAS, 247, 19.ADSGoogle Scholar
  10. Dunlop, J.S. & Peacock, J.A., 1993. MNRAS, in press.Google Scholar
  11. Dunlop, J.S., Taylor, G.L., Hughes, D.H. & Robson, E.I., 1993. MNRAS, in press.Google Scholar
  12. Eales, S.A., Rawlings, S., Dickinson, M., Spinrad, H., Hill, G.J. & Lacy, M., 1993. ApJ, in press.Google Scholar
  13. Ellingson, E., Yee, H.K.C. & Green, R.F., 1991. ApJ, 371, 41.ADSCrossRefGoogle Scholar
  14. Haehnelt, M.G. & Rees, M.J., 1993. MNRAS, in press.Google Scholar
  15. Hartwick, F.D.A. & Schade, D., 1990. Ann. Rev. A&A, 28, 437.ADSCrossRefGoogle Scholar
  16. Hawkins, M.R.S. & Veron, P., 1993. MNRAS, 260, 202.ADSGoogle Scholar
  17. Hazard, C., McMahon, R.G. & Sargent, W., 1986. Nature, 322, 38.ADSCrossRefGoogle Scholar
  18. Hewett, P.C., Foltz, C.B. & Chaffee, F.H., 1993. ApJ, 406, L43.ADSCrossRefGoogle Scholar
  19. Irwin, M.J., McMahon, R.G. & Hazard, C., 1991. In The Space Distribution of Quasars, ASP Conf. Ser. No. 27, p. 117, ed. Crampton, D., ASP.Google Scholar
  20. Kashlinsky, A., 1993. ApJ, 406, L1.ADSCrossRefGoogle Scholar
  21. Kormendy, J., 1992. In: Testing the AGN Paradigm, p.23, eds. Holt, S.S., Neff, S., Urry, C.M., American Institute of Physics, New York.Google Scholar
  22. Kron, R.G., Bershady, M.A., Munn, J.A., Smetanka, J.J., Majewski, S. & Koo, D.C., 1991. In The Space Distribution of Quasars, ASP Conf Ser. No. 21, p. 32, ed. Crampton, D., ASP.Google Scholar
  23. Miller, L., Peacock, J.A. & Mead, A.R.G., 1990. MNRAS, 244, 207.ADSGoogle Scholar
  24. Miller, L., Goldschmidt, P., La Franca, F. & Cristiani, S., 1993. In: Observational Cosmology, ASP Conf. Sen., in press.Google Scholar
  25. Mitchell, P.S., Miller, L. & Boyle, B.J., 1990. MNRAS, 244, 1.ADSGoogle Scholar
  26. Padovani, P. & Urry, C.M., 1992, ApJ, 387, 449.ADSCrossRefGoogle Scholar
  27. Peacock, J.A., 1987, In: Astrophysical Jets and Their Engines, NATO ASI Series C, Vol. 208, p.171, ed. Kundt, W., Reidel.Google Scholar
  28. Peacock, J.A., 1993. In: The Nature of Compact objects in AGN, Proc. 33 rd Herstmonceux Conf., in press.Google Scholar
  29. Rawlings, S. & Saunders, R., 1991. Nature, 349, 138.ADSCrossRefGoogle Scholar
  30. Rowan-Robinson, M., Benn, C.R., Lawrence, A., McMahon, R.G. & Broadhurst, T.J., 1993. MNRAS, in press.Google Scholar
  31. Saunders, W., Rowan-Robinson, M., Lawrence, A., Efstathiou, G., Kaiser, N., Ellis, R.S. & Frenk, C.S., 1990. MNRAS, 242, 318.ADSGoogle Scholar
  32. Schmidt, M., Schneider, D. & Gunn, J., 1991. In The Space Distribution of Quasars, ASP Conf Ser. No. 21, p. 109, ed. Crampton, D., ASP.Google Scholar
  33. Small, T.A. & Blandford, R.D., 1992. MNRAS, 259, 725.ADSGoogle Scholar
  34. Sopp, H.M. & Alexander, P.A., 1991. MNRAS, 251, 14P.ADSGoogle Scholar
  35. Wall, J.V., 1983. In The Origin & Evolution of Galaxies, NATO Advanced Study Institute Series, p.295, eds. Jones, B.J.T. & Jones, J.E., ReidelGoogle Scholar
  36. Warren, S.J. & Hewett, P.C., 1990. Rev. Mod. Phys., 53, 1093.Google Scholar
  37. Warren, S.J., Hewett, P.C., & Osmer, P.S., 1991. In The Space Distribution of Quasars, ASP Conf. Ser. No. 21, p.139, ed. Crampton, D., ASP.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1994

Authors and Affiliations

  • James S. Dunlop
    • 1
  1. 1.Astrophysics, Liverpool John Moores UniversityLiverpoolUK

Personalised recommendations