The results from deep <i>K</i> –band imaging of the most luminous known radio galaxies at <i>z</i> ~ 2 and the brightest known submillimeter sources in the 8-mJy survey are presented. The luminosities of the submillimeter galaxies are found to be ~ 1.5 magnitudes brighter than Lyman-break galaxies at comparable redshifts, indicating that submillimeter galaxies are significantly more massive. Finally, surface mass densities for both source types are found to be consistent with quiescent elliptical galaxies at high redshift, and not star-forming or Lyman-break galaxies. The results are presented of a study that uses the 3CRR sample of radio-loud active galactic nuclei to investigate the evolution of the black-hole:spheroid mass ratio in the most massive early-type galaxies from 0 < <i>z</i> < 2. Radio-loud unification is exploited to obtain virial (linewidth) black hole mass estimates from the 3CRR quasars, and stellar mass estimates from the 3CRR radio galaxies, thereby providing black hole and stellar mass estimates for a single population of early-type galaxies. The detection of evolution in the 3CRR black-hole:spheroid mass ratio further strengthens the evidence that, at least for massive early-type galaxies, the growth of the central supermassive black hole may be completed before that of the host spheroid. The results from an ongoing project to constrain the evolution of the black-hole:spheroid mass ratio at <i>z</i> = 3&4 are presented. At these redshifts quasars and their hosts provide a unique window on this evolution, as the only class of object in which both galaxy and black hole masses can be directly measured. These pilot data represent the first attempt to constrain the black-hole:spheroid mass ratio as part of a statistically significant sample at <i>z</i> = 3&4, a crucial epoch of galaxy formation and evolution.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:662735 |
| Date | January 2007 |
| Creators | Targett, T. A. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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