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Giant outflows in z~2 radio galaxies: The smoking gun of AGN feedback in the early universe

2009/06/16 by N. P. H. Nesvadba, Nesvadba, N. P. H.
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena

paper · pdf · doi:10.48550/arxiv.0906.2900

openalex publication_date 2009/06/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

AGN feedback is now a major component of models of galaxy evolution. Using near-infrared imaging spectroscopy on the VLT we identify kpc-sized outflows of few x 1010 Ms of ionized gas in powerful radio galaxies at z~2-3. Velocity fields are consistent with bipolar outflows, with total velocity offsets of ~1000 km s-1. FWHMs ~1000 km s-1 suggest strong turbulence. IRAM follow-up observations of parts of the sample suggest a remarkable deficit in cold molecular relative to ionized gas, which may imply that significant fractions of the interstellar medium of these galaxies are participating in the winds. Kinetic energies of the gas correspond to ~0.2% of the rest-mass equivalent of the mass of the supermassive black hole, roughly in agreement with model predictions. We also report the detection of a massive reservoir of few x 1010 Ms of cold molecular gas in the halo of the z=2.6 radio galaxy TXS0828+193 with the IRAM Plateau de Bure Interferometer. The gas is at a distance of ~90 kpc from the radio galaxy, and does not appear associated with a significant stellar mass > few x109 Ms. It is near one of the radio hot spots, and at a very similar redshift to the diffuse, Mpc-sized halo of ionized gas surrounding the radio galaxy. This may be the first sign that the jets of powerful radio galaxies at z~2 may interact efficiently with the intracluster medium, somewhat in analogy with the filaments of multiphase gas in nearby galaxy clusters which are being heated by the powerful AGN of their central galaxies.

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