A D-term Modeling Code (DMC) for simultaneous calibration and full-Stokes imaging of very long baseline interferometric data

TL;DR

DMC is a novel polarimetric imaging tool for VLBI data that simultaneously reconstructs the emission structure and calibration parameters, providing uncertainty quantification through Bayesian posterior exploration.

Contribution

It introduces a Bayesian framework using Hamiltonian Monte Carlo for joint imaging and calibration of VLBI data, enabling uncertainty assessment.

Findings

Accurately recovers image structure and calibration parameters.

Provides natural quantification of uncertainties in imaging and calibration.

Demonstrates effectiveness on synthetic and real datasets.

Abstract

In this paper we present DMC, a model and associated tool for polarimetric imaging of very long baseline interferometry datasets that simultaneously reconstructs the full-Stokes emission structure along with the station-based gain and leakage calibration terms. DMC formulates the imaging problem in terms of posterior exploration, which is achieved using Hamiltonian Monte Carlo sampling. The resulting posterior distribution provides a natural quantification of uncertainty in both the image structure and in the data calibration. We run DMC on both synthetic and real datasets, the results of which demonstrate its ability to accurately recover both the image structure and calibration quantities as well as to assess their corresponding uncertainties. The framework underpinning DMC is flexible, and its specific implementation is under continued development.