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Paper: |
CO Emission from Powerful Radio Galaxies at Low and High Redshift |
Volume: |
156, Highly Redshifted Radio Lines |
Page: |
74 |
Authors: |
Evans, A. S. |
Abstract: |
CO observations of 0 < z < 4 radio galaxies are presented. The LCO upper limits for the high-redshift powerful radio galaxies (HzPRGs: z > 1, P_{408{MHz}} > 1027 W Hz^{-1}) are consistent with no evolution in molecular gas (H_2) mass with redshift and/or radio power. Of the low-redshift powerful radio galaxies (LzPRGs: z < 0.2, P_{408{MHz}} > 10^{23.5} W Hz^{-1}) observed, only one FR II galaxy has been detected in CO, whereas 50% of the radio-compact (FC) and FR I galaxies have been detected. The CO and imaging data to date imply that either FR II galaxies result from mergers of gas-poor galaxies relative to FC/FR I galaxies, or that some FC/FR I galaxies evolve into FR II galaxies. In either scenario, the radio activity in powerful radio galaxies is most likely triggered by a merger event and H_2 may be the fuel for the active galactic nucleus (AGN) in the early stages of the merger. |
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