Feature Guided Training and Rotational Standardisation for the Morphological Classification of Radio Galaxies
arXiv:2304.05095 · doi:10.1093/mnras/stad989
Abstract
State-of-the-art radio observatories produce large amounts of data which can be used to study the properties of radio galaxies. However, with this rapid increase in data volume, it has become unrealistic to manually process all of the incoming data, which in turn led to the development of automated approaches for data processing tasks, such as morphological classification. Deep learning plays a crucial role in this automation process and it has been shown that convolutional neural networks (CNNs) can deliver good performance in the morphological classification of radio galaxies. This paper investigates two adaptations to the application of these CNNs for radio galaxy classification. The first adaptation consists of using principal component analysis (PCA) during preprocessing to align the galaxies' principal components with the axes of the coordinate system, which will normalize the orientation of the galaxies. This adaptation led to a significant improvement in the classification accuracy of the CNNs and decreased the average time required to train the models. The second adaptation consists of guiding the CNN to look for specific features within the samples in an attempt to utilize domain knowledge to improve the training process. It was found that this adaptation generally leads to a stabler training process and in certain instances reduced overfitting within the network, as well as the number of epochs required for training.
20 pages, 17 figures, this is a pre-copyedited, author-produced PDF of an article accepted for publication in the Monthly Notices of the Royal Astronomical Society
References in corpus (17)
- Array Programming with NumPy
- Machine learning and deep learning
- Active Galactic Nuclei: what's in a name?
- Science with ASKAP - the Australian Square Kilometre Array Pathfinder
- The Last of FIRST: The Final Catalog and Source Identifications
- A pilot study of the radio-emitting AGN population: the emerging new class of FR0 radio-galaxies
- Classifying Radio Galaxies with Convolutional Neural Network
- FR0CAT: a FIRST catalog of FR0 radio galaxies
- FRICAT: A FIRST catalog of FRI radio galaxies
- An automatic taxonomy of galaxy morphology using unsupervised machine learning
- CNN Architecture Comparison for Radio Galaxy Classification
- Fanaroff-Riley classification of radio galaxies using group-equivariant convolutional neural networks
- Attention-gating for improved radio galaxy classification
- WATCAT: a tale of wide-angle tailed radio galaxies
- Science with the Murchison Widefield Array: Phase I Results and Phase II Opportunities
- Comparing Pattern Recognition Feature Sets for Sorting Triples in the FIRST Database
- The Combined NVSS-FIRST Galaxies (CoNFIG) Sample - I. Sample Definition, Classification and Evolution