Over-resolution of compact sources in interferometric observations
Journal 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: high angular resolution