Speaker: James Pearson (Open University)

Date: Wednesday 17 April 2024

Time: 15:00

Location: Berry lecture theatre (3.21)

A large population of strongly lensed submm galaxies in Euclid and how to find them with citizen science

Models of deep JCMT surveys predict that about 1% of faint sub-millimetre galaxies will be strongly gravitationally lensed, tending to appear in near-infrared channels only. I will discuss my discovery of a compelling gravitational lens system confirming this prediction, identified through public JWST imaging of a 450-micron source in the SCUBA-2 Ultra Deep Imaging EAO Survey (STUDIES) catalogue. Extrapolating this, we predict tens of thousands of strongly lensed near-infrared galaxies in the Euclid-Wide survey that will be transformative for strong lensing science. One method to find these comparatively rare objects is through citizen science projects, such as Galaxy Zoo which asks the public to classify galaxies based on their visual morphologies in order to study galaxy formation and evolution. I will also discuss leading one of its latest iterations, Galaxy Zoo: Cosmic Dawn, which uses images of the Euclid Deep Field North (EDF-N) taken by the Hyper Suprime-Cam (HSC) as part of the Hawaii Two-0 (H20) Cosmic Dawn survey, therefore acting as a precursor for Euclid follow-up imaging of rare and interesting objects.