SAND: An automated VLBI imaging and analysing pipeline - I. Stripping component trajectories

TL;DR

This paper introduces SAND, an automated pipeline for VLBI data reduction and analysis, enabling efficient, objective multi-epoch, multi-band imaging and jet component trajectory detection.

Contribution

The paper presents a novel automated VLBI data reduction pipeline with a regression strip algorithm for objective jet component trajectory analysis.

Findings

Automated pipeline reduces manual effort and increases objectivity.

Provides comprehensive outputs including images, models, and spectra.

Introduces a regression strip algorithm for jet component trajectory detection.

Abstract

We present our implementation of an automated VLBI data reduction pipeline dedicated to interferometric data imaging and analysis. The pipeline can handle massive VLBI data efficiently which makes it an appropriate tool to investigate multi-epoch multiband VLBI data. Compared to traditional manual data reduction, our pipeline provides more objective results since less human interference is involved. Source extraction is done in the image plane, while deconvolution and model fitting are done in both the image plane and the uv plane for parallel comparison. The output from the pipeline includes catalogues of CLEANed images and reconstructed models, polarisation maps, proper motion estimates, core light curves and multi-band spectra. We have developed a regression strip algorithm to automatically detect linear or non-linear patterns in the jet component trajectories. This algorithm offers an objective method to match jet components at different epochs and determine their proper motions.