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Paper: |
Radio galaxies and galaxy formation |
Volume: |
21, The Space Distribution of Quasars |
Page: |
379 |
Authors: |
Peacock, John |
Abstract: |
Radio galaxies at large redshift constrain galaxy formation models in two ways: (1) through their comoving density; (2) through the ages of their stellar population. The observed density of radio galaxies at z roughly 4 sets important limits on power-spectrum normalization in hierarchical models. CDM models probably require a low degree of bias to survive. The 'alignment effect' has been used to argue that observed high-z radio galaxies are young objects in which the majority of stars are generated by the jets from the AGN. However, new data show that alignments are confined to sources of the most extreme radio power. It therefore seems likely that the stellar populations in high-z radio galaxies are old - as expected in hierarchical models for galaxy formation. |
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