Abstract
Large deep Westerbork samples of radio sources have been optically identified on Palomar Schmidt and Kitt Peak 4-m plates. The radio galaxy population shows no evolution from z = 0 to z ≃ 0.25, then rises steeply in proper density beyond that epoch, attaining enhancement factors ∼ 30 at z ≳ 0.5. These distant radio galaxies show a striking blue excess of as much as two magnitudes.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Willis, A. G., Oosterbaan, C. E. & de Ruiter, H. R. Astr. Astrophys. Suppl. 25, 453–505 (1976).
Katgert, P. Astr. Astrophys. 38, 87–104 (1975).
de Ruiter, H. R., Willis, A. G. & Arp, H. C. Astr. Astrophys. Suppl. 28, 211–293 (1977).
Willis, A. G. & de Ruiter, H. R. Astr. Astrophys. Suppl. 29, 103–116 (1977).
Katgert, P., de Bruyn, A. G. & Willis, A. G. Astr. Astrophys. Suppl. 36, 213–225 (1979).
de Ruiter, H. R. thesis, Leiden Univ. (1978).
Sandage, A. Astrophys. J. 178, 25–44 (1972).
Sandage, A. Astrophys. J. 183, 731–742 (1973).
Pence, W. Astrophys. J. 203, 39–51 (1976).
Code, A. D. & Welch, G. A. Wisconsin Astrophysics Preprint No. 43 (1977).
Boksenberg, A. et al. Nature 275, 404–414 (1978).
Kristian, J., Sandage, A. & Westphal, J. A. Astrophys. J. 221, 383–394 (1978).
Butcher, H. & Oemler, A. Astrophys. J. 219, 18–30 (1978).
Kron, R. G. thesis, Univ. California, Berkeley (1978).
Auriemma, C. et al. Astr. Astrophys. 57, 41–50 (1977).
Colla, G. et al. Astr. Astrophys. 38, 209–223 (1975).
Meier, D. L., Ulrich, M. H., Fanti, R., Gioia, I. & Lari, C. Astr. Astrophys. (in the press).
Robertson, J. G. Mon. Not. R. astr. Soc. 182, 617–628 (1978).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Katgert, P., de Ruiter, H. & van der Laan, H. Redshift dependence of colour and space density of radio galaxies. Nature 280, 20–23 (1979). https://doi.org/10.1038/280020a0
Received:
Accepted:
Issue date:
DOI: https://doi.org/10.1038/280020a0
