Bayesian Image Reconstruction of MOJAVE AGN VLBI Data

Master Colloquium
Sviatoslav Khukhlaev
SCHEDULED
MPIfR

MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) was organized as a long-term monitoring program to repeatedly image a large sample of bright, radio-loud AGN at milliarcsecond resolution, and these observations continue today. Until now, all MOJAVE images have been reconstructed using the traditional imaging algorithm CLEAN, which defines the final image resolution by the restoring beam and does not provide any uncertainty estimations. In turn, modern Bayesian algorithms, for example RESOLVE, are capable of retrieving finer and more continuous structures, especially in bright regions of the source. They also naturally provide uncertainty estimates for the reconstructions, which are invaluable for any statistical analysis. In this thesis, I use RESOLVE in an automatic regime on all 12285 MOJAVE VLBI observations and compare the performance with CLEAN. I show that RESOLVE is generally able to reconstruct images with high accuracy and uncover small-scale details. I fit core components in the image domain and highlight the consistency between the estimated brightness temperatures and those from the analogous visibility-domain approach. These findings indicate the potential of using modern methods alongside CLEAN to improve the image-domain analysis.

TBD

Main Colloquium
Prof. Dr. Prasenjit Saha
SCHEDULED
University of Zurich, Switzerland

TBD