Difference imaging in radio interferometry
O. Wucknitz [1]
- Argelander-Institut für Astronomie, Auf dem Hügel 71, 53121 Bonn, Germany
Abstract
A promising approach to find gravitational lenses is to select objects with time-variable extended emission. Since intrinsic variability (but also scintillation) is generally only possible for compact sources, the signature of extended variability provides evidence for several compact components with small separations. In a good fraction of these objects, the multiple images will just be an illusion caused by a gravitational lens.
I discuss the development of difference imaging algorithms in radio interferometry. Independent deconvolution with subsequent subtraction is not an option, because difference images produced in this way would be dominated by deconvolution errors.
A multi-channel adaption of CLEAN is a viable alternative. The availability of powerful deconvolution techniques for variable sources may also be of relevance for other fields of research.
A slightly more detailed version of this talk was presented as a lunch colloquium.
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Script last modified on 7 Sep 2010
Last change to this data base entry on 8 Oct 2008