Tracing the Faint Universe: Low-Surface-Brightness Galaxies in Wide-Field SurveysRecording

by Dr Hareesh Thuruthipilly (University of Valladolid, Spain)

Thursday Dec 4, 2025, 1:00 PM → 2:30 PM Europe/Madrid

00.303.0 - Aula 13 (Facultad de Ciencias Físicas)

Low-surface-brightness galaxies (LSBGs), generally defined as galaxies fainter than the night sky, are crucial for advancing our understanding of galaxy formation and evolution. Surveys such as Legacy Survey of Space and Time (LSST) and Euclid are expected to detect more than 200,000 LSBGs. However, their identification remains challenging due to contamination in the low-surface-brightness regime. To address this, we have developed a deep learning framework for LSBG detection across multiple surveys using transfer learning. Applying this method to Kilo degree survey (KiDS), we identified ~20,000 LSBGs and derived their structural and photometric properties. To further test its adaptability, we applied it to deep HSC imaging of eight clusters, including Coma and Hydra, reaching depths comparable to the LSST 10-year survey. This yielded over 2,500 ultra-diffuse galaxy (UDG) candidates. Our framework offers a scalable solution for LSBG detection and paves the way for large-scale studies with LSST and Euclid.

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