| Atomic hydrogen in the one-sided "compact double" radio galaxy 2050+364 (2006) | |||||||||||||||
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| Astronomy Astrophysics manuscript DOI will inserted hand later April Atomic hydrogen the one sided compact double radio galaxy Vermeulen Labiano Barthel Baum Vries and Dea arXiv astro Oct Netherl Foundation for Research Astronomy ASTRON Box Dwingeloo The Netherlands Kapteyn Astronomical Institute Box Groningen The Netherlands Space Telescope Science Institute Baltimore Center for Imaging Science Rochester Inst Techn Lomb Memorial Drive Rochester A Lawrence Livermore National Laboratories Department Physics Rochester Institute Technology Rochester A Received Accepted Abstract European VLBI Network spectral imaging the compact double radio source the UHF band MHz has resolved the absorbing region and has shown faint continuum component the North addition the well known East West double examination VLBI continuum images multiple frequencies suggests that may well one sided core jet source which appears double over limited frequency range One the dominant features would then the innermost visible portion the jet and could adjacent the canonical radio core The other probably related shocks sudden bend the jet towards extended steep spectrum region remarkably deep and narrow absorption line component extends over the entire projected extent coincides velocity with the III optical doublet lines within This absorption could arise the atomic cores NLR clouds and the motion the NLR then remarkably coherent both along the line sight and across projected distance the plane the sky Broade. European VLBI Network spectral imaging of the “compact double” radio source 2050+364 in the UHF band at 1049 MHz has resolved the HI absorbing region, and has shown a faint continuum component to the North (N), in addition to the well-known East-West double (E, W). Re-examination of VLBI continuum images at multiple frequencies suggests that 2050+364 may well be a one-sided core-jet source, which appears as a double over a limited frequency range. One of the dominant features,W, would then be the innermost visible portion of the jet, and could be at or adjacent to the canonical radio core. The other, E, is probably related to shocks at a sudden bend of the jet, towards extended steep-spectrum region N. A remarkably deep and narrow HI absorption line component extends over the entire projected extent of 2050+364. It coincides in velocity with the [OIII] optical doublet lines to within 10 kms^−1. This HI absorption could arise in the atomic cores of NLR clouds, and the motion in the NLR is then remarkably coherent both along the line-of-sight and across a projected distance of > 300 pc on the plane of the sky. Broader, shallower HI absorption at lower velocities covers only the plausible core area W. This absorption could be due to gas which is either being entrained by the inner jet or is flowing out from the accretion region; it could be related to the BLR (Refer to PDF file for exact formulas).. The European VLBI Network is a joint facility of European, Chinese, South African and other astronomy institutes funded by their national research councils. The WSRT is operated by ASTRON (The Netherlands Foundation for Research in Astronomy) with support from the Netherlands Foundation for Scientific Research (NWO). The data were correlated at the NRAO, Socorro processor. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration in the United States of America. We thank Dr. Raffaella Morganti for useful discussions, and the referee, Dr. Seiji Kameno, for a very thorough report, which has led to considerable enhancements to this paper. | |||||||||||||||
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