2006/11/24 by A. Humphrey, M. Villar-Martin., M. Villar‐Martín +6 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.11344.x
published as Mon.Not.Roy.Astron.Soc.375:705-714,2007 · Accepted for publication in MNRAS
arxiv created 2006/11/24 · openalex publication_date 2007/01/13 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
We present an investigation into the possible relationship between side-to-side asymmetries of powerful radio galaxies at high redshift, with the goal of understanding the geometry, orientation and gas dynamics of these sources. Our sample consists of 11 radio galaxies at 2.3 ≤z≤ 3.6 previously known to have giant, kinematically quiescent nebulae. We identify several correlated asymmetries: on the side of the brightest radio jet and hotspot (i) the redshift of the kinematically quiescent nebula is highest, (ii) Lyα is brighter relative to the other lines and continuum, (iii) the radio spectrum is flattest and (iv) the radio structure has its highest polarization. These asymmetries are not found to be correlated with either the radio arm length asymmetry or the brightness asymmetry of the UV–optical emitting material. The correlation between the radio brightness asymmetry and the radial velocity of the quiescent gas also appears to be present in powerful radio galaxies with 0 ≲z≲ 1. Collectively, these asymmetries are most naturally explained as an effect of orientation, with the quiescent nebulae in infall: this is the first study to distinguish between the rotation, infall, outflow and chaotic motion scenarios for the kinematically quiescent emission-line nebulae around powerful active galactic nuclei.