Measuring the Intracluster Light Fraction with Machine Learning

The intracluster light (ICL) is an important tracer of a galaxy cluster’s history and past interactions. However, only small samples have been studied to date due to its very low surface brightness and the heavy manual involvement required for the majority of measurement algorithms. Upcoming large i...

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Detalles Bibliográficos
Autores: Canepa, Louisa, Brough, Sarah, Lanusse, Francois, Montes, Mireia, Hatch, Nina
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/392394
Acceso en línea:http://hdl.handle.net/10261/392394
https://api.elsevier.com/content/abstract/scopus_id/85218951159
Access Level:acceso abierto
Palabra clave:Galaxy clusters
Galactic and extragalactic astronomy
Convolutional neural networks
http://astrothesaurus.org/uat/584
http://astrothesaurus.org/uat/563
http://astrothesaurus.org/uat/1938
Descripción
Sumario:The intracluster light (ICL) is an important tracer of a galaxy cluster’s history and past interactions. However, only small samples have been studied to date due to its very low surface brightness and the heavy manual involvement required for the majority of measurement algorithms. Upcoming large imaging surveys such as the Vera C. Rubin Observatory’s Legacy Survey of Space and Time (LSST) are expected to vastly expand available samples of deep cluster images. However, to process this increased amount of data, we need faster, fully automated methods to streamline the measurement process. This paper presents a machine learning model designed to automatically measure the ICL fraction in large samples of images, with no manual preprocessing required. We train the fully supervised model on a training data set of 50,000 images with injected artificial ICL profiles. We then transfer its learning onto real data by fine-tuning with a sample of 101 real clusters with their ICL fraction measured manually using the surface brightness threshold method. With this process, the model is able to effectively learn the task and then adapt its learning to real cluster images. Our model can be directly applied to Hyper Suprime-Cam images, processing up to 500 images in a matter of seconds on a single GPU, or fine-tuned for other imaging surveys such as LSST, with the fine-tuning process taking just 3 minutes. The model could also be retrained to match other ICL measurement methods. Our model and the code for training it are made available on GitHub.