Resolving the blazar CGRaBS J0809+5341 in the presence of telescope systematics

Understand

We analyse Very Long Baseline Interferometry (VLBI) observations of the blazar CGRaBS J0809+5341 using Bayesian inference methods.

• The observation was carried out at 5 GHz using 8 telescopes that form part of the European VLBI Network.
• Imaging and deconvolution using traditional methods imply that the blazar is unresolved.
• To search for source structure beyond the diffraction limit, we perform Bayesian model selection between three source models (point, elliptical Gaussian, and circular Gaussian).