Identification of multicomponent LOFAR sources with multimodal deep learning

Monthly Notices of the Royal Astronomical Society, vol. 532, pp. 3322–3340

Abstract

ABSTRACT Modern high-sensitivity radio telescopes are discovering an increased number of resolved sources with intricate radio structures and fainter radio emissions. These sources often present a challenge because source detectors might identify them as separate radio sources rather than components belonging to the same physically connected radio source. Currently, there are no reliable automatic methods to determine which radio components are single radio sources or part of multicomponent sources. We propose a deep-learning classifier to identify those sources that are part of a multicomponent system and require component association on data from the LOFAR Two-Metre Sky Survey. We combine different types of input data using multimodal deep learning to extract spatial and local information about the radio source components: a convolutional neural network component that processes radio images is combined with a neural network component that uses parameters measured from the radio sources and their nearest neighbours. Our model retrieves 94 per cent of the sources with multiple components on a balanced test set with 2683 sources and achieves almost 97 per cent accuracy in the real imbalanced data (323 103 sources). The approach holds potential for integration into pipelines for automatic radio component association and cross-identification. Our work demonstrates how deep learning can be used to integrate different types of data and create an effective solution for managing modern radio surveys.

Authors 6

1. L. Alegre corresponding

   Royal Observatory · University of Edinburgh

   Affiliation as printed

   Institute for Astronomy, School of Physics and Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ , UK

2. P. N. Best

   Royal Observatory · University of Edinburgh

   Affiliation as printed

   Institute for Astronomy, School of Physics and Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ , UK

3. J. Sabater

   Royal Observatory · UK Astronomy Technology Centre · University of Edinburgh

   Affiliation as printed

   Institute for Astronomy, School of Physics and Astronomy, University of Edinburgh, Royal Observatory Edinburgh, Blackford Hill, Edinburgh EH9 3HJ , UK

   UK Astronomy Technology Centre, Royal Observatory , Blackford Hill, Edinburgh, EH9 3HJ , UK

4. Huub J. A. Röttgering Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory, Leiden University , PO Box 9513, NL-2300 RA Leiden , The Netherlands

5. M. J. Hardcastle

   University of Hertfordshire

   Affiliation as printed

   Department of Physics, Centre for Astrophysics Research, Astronomy and Mathematics, University of Hertfordshire , College Lane, Hatfield AL10 9AB , UK

6. Wendy L. Williams

   SKA Observatory

   Affiliation as printed

   SKA Observatory, Jodrell Bank, Lower Withington , Macclesfield SK11 9FT , UK