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Astron. Astrophys. 346, 392-396 (1999)
Dual-frequency VLBI observations of the gravitational lens system PKS 1830-211
J.C. Guirado 1,
D.L. Jones 2,
L. Lara 3,
J.M. Marcaide 1,
R.A. Preston 2,
A.P. Rao 4 and
W.A. Sherwood 5
1 Departamento de Astronomía, Universitat de València, E-46100 Burjassot, Valencia, Spain
2 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
3 Instituto de Astrofísica de Andalucía, CSIC, Apdo. Postal 3004, E-18080 Granada, Spain
4 National Centre for Radio Astrophysics, Tata Institute, Pune 411007, India
5 Max-Planck-Institut fuer Radioastronomie, D-53121 Bonn, Germany
Received 13 August 1998 / Accepted 9 March 1999
Abstract
From simultaneous 8.4 and 2.3 GHz VLBA observations we have studied
the morphology and properties of the compact components of the
gravitational lens PKS 1830-211. We have found that the size of the
southwest component increases as ![[FORMULA]](img1.gif)
,
most probably due to scattering by interstellar plasma, while the size
of the northeast component does not increase with such wavelength
dependence. The small separation between both lensed components,
compared with the typical size of scattering clumps in our Galaxy,
suggests that the scattering material is located in the lensing
galaxy, rather than in the Milky Way. Within the uncertainties, the
flux-density ratios of the brightest feature in the two compact
components for the two frequency bands agree with each other, as
expected for images of the same background feature.
Key words: cosmology: gravitational
lensing 
galaxies: quasars: individual: PKS 1830-211
Send offprint requests to: J.C. Guirado (jcg@vlbi.uv.es)
Contents
© European Southern Observatory (ESO) 1999
Online publication: May 21, 1999
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