Over-resolution of compact sources in interferometric observations
Review article, 2012

We review the effects of source size in interferometric observations and focus on the cases of very compact sources. If a source is extremely compact and/or weak (so it is not possible to detect signature of source structure in the visibilities) we describe a test of hypothesis that can be used to set a strong upper limit to the size of the source. We also estimate the minimum possible size of a source whose structure can still be detected by an interferometer (i.e., the maximum theoretical over-resolution power of an interferometer), which depends on the overall observing time, the compactness in the array distribution, and the sensitivity of the receivers. As a result, and depending on the observing frequency, the over-resolution power of forthcoming ultra-sensitive arrays, like the Square Kilometer Array (SKA), may allow us to study details of sources at angular scales down to a few micro-arcsec.

techniques: interferometric

techniques: high angular resolution

instrumentation: interferometers


Ivan Marti-Vidal

Chalmers, Earth and Space Sciences, Onsala Space Observatory

Miguel Angel Perez-Torres

Institute of Astrophysics of Andalusia (IAA)

A. P. Lobanov

Max Planck Society

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 541 A135- A135

Subject Categories

Astronomy, Astrophysics and Cosmology

Probability Theory and Statistics


Basic sciences


Onsala Space Observatory



More information

Latest update