Wide-field VLBI imaging of M31 - first results

TL;DR

This paper demonstrates the use of advanced wide-field VLBI imaging techniques with VLBA and EVN to study the entire M31 galaxy at high resolution, revealing compact radio components across its disk.

Contribution

It introduces new wide-field VLBI imaging methods applied to M31, enabling high-resolution, full-disk radio surveys of nearby galaxies.

Findings

First high-resolution wide-field images of M31

Identification of compact radio sources within M31

Demonstration of the new imaging technique's feasibility

Abstract

One of our closest neighbours, the Andromeda Galaxy (M31) has been the subject of numerous large area studies across the entire spectrum, but so far full-disk radio surveys have been conducted only at low resolution. The new wide-field capabilities of the DiFX software correlator present the possibility of imaging the entire primary beam of a VLBI array, thus enabling a high resolution wide-field study of the entire galaxy. Using the VLBA and EVN, pilot observations of M31 have been carried out with the aim of using these new wide-field techniques to characterise the population of compact components at VLBI resolution both within and behind one of our nearest neighbours. This contribution describes the observations carried out, the preliminary processing and first results.