Atomic hydrogen in the one-sided “compact double” radio galaxy 2050+364

Free access article

Issue		A&A Volume 447, Number 2, February IV 2006


Page(s)		489 - 498
Section		Extragalactic astronomy
DOI		http://dx.doi.org/10.1051/0004-6361:20053857

A&A 447, 489-498 (2006)
DOI: 10.1051/0004-6361:20053857

Atomic hydrogen in the one-sided "compact double" radio galaxy 2050+364

R. C. Vermeulen¹, A. Labiano^{2, 3}, P. D. Barthel², S. A. Baum^{4, 3}, W. H. de Vries⁵ and C. P. O'Dea^{6, 3}

¹ Netherl. Foundation for Research in Astronomy (ASTRON), PO Box 2, 7990 AA Dwingeloo, The Netherlands
e-mail: rvermeulen@astron.nl
² Kapteyn Astronomical Institute, PO Box 800, 9700 AV Groningen, The Netherlands
e-mail: labiano@astro.rug.nl
³ Space Telescope Science Institute, Baltimore, MD 21218, USA
⁴ Center for Imaging Science, Rochester Inst. of Techn., 54 Lomb Memorial Drive, Rochester, NY, 14623, USA
⁵ Lawrence Livermore National Laboratories, USA
⁶ Department of Physics, Rochester Institute of Technology, Rochester, NY, 14623, USA

(Received 19 July 2005 / Accepted 14 October 2005 )

Abstract
Aims.Localise and study the redshifted 21 cm $\ion{H}{i}$ absorption and the radio morphology of 2050+364 .
Methods.European VLBI Network UHF band (1049 MHz) spectral imaging, and examination of VLBI continuum images at multiple frequencies.
Results. 2050+364 may well be a one-sided core-jet source, which appears as a double (the well-known East-West component pair E, W) over a limited frequency range. W would then be the innermost visible portion of the jet, and could be at or adjacent to the canonical radio core. E is probably related to shocks at a sudden bend of the jet, towards an additional Northern extended steep-spectrum area (N), visible in our 1049 MHz image. Our observations have resolved the $\ion{H}{i}$ absorbing region. A remarkably deep and narrow line component is present over the entire projected extent of 2050+364 . It coincides in velocity with the [ $\ion{O}{iii}$ ] optical doublet lines to within 10 km s^-1. This $\ion{H}{i}$ 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 $\ion{H}{i}$ 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.

Key words: galaxies: active -- galaxies: ISM -- galaxies: individual: 2050+364 -- galaxies: jets -- radio lines: galaxies

SIMBAD Objects

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.