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Astrophysics and Space Science

, Volume 228, Issue 1–2, pp 195–202 | Cite as

The implications of intrinsic luminosity evolution on the value of the density parameter (Ω) and the evolution of radio sizes of radio galaxies and quasars

  • A. A. Ubachukwu
Article

Abstract

The implications of the intrinsic luminosity evolution with cosmological epoch on the value of the density parameter (Ω) and evolution of radio sizes of extragalactic radio sources have been considered. It is shown that a power law evolution model of the sortP ∼ (1 +z) β can be used to contrain the value of Ω. In the presence of a strong luminosity evolution, the model yields an upper limit of Ω ∼ 0.5.

It is also shown that the angular diameter redshift (θ – z) relation for quasars can be interpreted in terms of the assumed luminosity evolution combined with a luminosity-linear size correlation with little or no linear size evolution required. On the other hand, strong linear size evolution is needed to explain theθ – z data for radio galaxies independent of luminosity.

Keywords

Evolution Model Radio Source Linear Size Density Parameter Radio Galaxy 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Barthel, P.D. and Miley, G.K.: 1988,Nat. 333, 319.Google Scholar
  2. Gopal-Krishna and Wiita, P.J.: 1987,Monthly Notices Roy. Astro. Soc. 226, 531.Google Scholar
  3. Jenkins, C.J., Pooley, G.G., and Riley, J.M.: 1977,Monthly Notices Roy. Astr. Soc. 84, 61.Google Scholar
  4. Kapahi, V.K.: 1987, in IAU Symp. 124, eds. A. Hewitet al., Reidel Pub. Comp., Dordrecht, p. 251.Google Scholar
  5. Kapahi, V.K.: 1989,Astr. J. 97, 1.Google Scholar
  6. Kolb, E.W. and Turner, M.S.: 1990, The early Universe. Monlo Park C.A. (Addison-Weasley).Google Scholar
  7. Kron, R.G., Koo, D.C., and Windhorst, R.A.: 1985,Astron. Astrophys. 146, 38.Google Scholar
  8. Laing, R.A. and Peacock, J.A.: 1980,Monthly Notices Roy. Astron. Soc. 190, 903.Google Scholar
  9. Miley, G.K.: 1968,Nat. 218, 933.Google Scholar
  10. Okoye, S.E. and Onuora, L.I.: 1982,Astrophys. J. 260, 37.Google Scholar
  11. Onuora, L.I. and Okoye, S.E.: 1983,Astrophys. J. 270, 360.Google Scholar
  12. Oort, M.J.A., Katgert, P., and Windhorst, R.A.: 1987,Astron. Astrophys. 199, 41.Google Scholar
  13. Peacock, J.A. and Wall, J.V.: 1981,Monthly Notices Roy. Astron. Soc. 194, 331.Google Scholar
  14. Peebles, P.J.E.: 1988,Publ. Astron. Soc. Pac. 100, 670.Google Scholar
  15. Singal, A.: 1993, A preprint submitted to Monthly Notices Roy. Astron. Soc.Google Scholar
  16. Ubachukwu, A.A., Okoye, S.E., and Onuora, L.I.: 1991,Astrophys. J. 383, 56.Google Scholar
  17. Ubachukwu, A.A., Okoye, S.E., and Onuora, L.I.: 1993,Proceedings of the Nigerian Academy of Science 5, 62.Google Scholar
  18. Windhorst, R.: 1984, Ph.D. Thesis, Leiden.Google Scholar
  19. Windhorst, R., Mathis, D., and Neuschaefer, L.: 1989, The Edwin Hubble Centenniel Symp., eds. R. Kronet al., ASP conf. series (Brigham Young Utah), p. 389.Google Scholar

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • A. A. Ubachukwu
    • 1
  1. 1.Space Research Centre, Department of Physics and AstronomyUniversity of NigeriaNsukkaNigeria

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