The impact of human expert visual inspection on the discovery of strong gravitational lenses

Rojas, Karina; Collett, Thomas E.; Ballard, Daniel; Magee, Mark R.; Birrer, Simon; Buckley-Geer, Elizabeth; Chan, James H.H.; Clément, Benjamin; Diego, José M.; Gentile, Fabrizio; González, Jimena; Joseph, Rémy; Mastache, Jorge; Schuldt, Stefan; Tortora, Crescenzo; Verdugo, Tomás; Verma, Aprajita; Daylan, Tansu; Millon, Martin; Jackson, Neal; Dye, Simon; Melo, Alejandra; Mahler, Guillaume; Ogando, Ricardo L.C.; Courbin, Frédéric; Fritz, Alexander; Herle, Aniruddh; Acevedo Barroso, Javier A.; Cañameras, Raoul; Cornen, Claude; Dhanasingham, Birendra; Glazebrook, Karl; Martinez, Michael N.; Ryczanowski, Dan; Savary, Elodie; Góis-Silva, Filipe; Ureña-López, L. Arturo; Wiesner, Matthew P.; Wilde, Joshua; Valim Calçada, Gabriel; Cabanac, Rémi; Pan, Yue; Sierra, Isaac; Despali, Giulia; Cavalcante-Gomes, Micaele V.; Macmillan, Christine; Maresca, Jacob; Grudskaia, Aleksandra; O'Donnell, Jackson H.; Paic, Eric; Niemiec, Anna; De La Bella, Lucia F.; Bromley, Jane; Williams, Devon M.; More, Anupr...

Abstract

We investigate the ability of human 'expert' classifiers to identify strong gravitational lens candidates in Dark Energy Survey like imaging. We recruited a total of 55 people that completed more than 25 per cent of the project. During the classification task, we present to the participants 1489 images. The sample contains a variety of data including lens simulations, real lenses, non-lens examples, and unlabelled data. We find that experts are extremely good at finding bright, well-resolved Einstein rings, while arcs with g-band signal to noise less than ∼25 or Einstein radii less than ∼1.2 times the seeing are rarely recovered. Very few non-lenses are scored highly. There is substantial variation in the performance of individual classifiers, but they do not appear to depend on the classifier's experience, confidence or academic position. These variations can be mitigated with a team of 6 or more independent classifiers. Our results give confidence that humans are a reliable pruning step for lens candidates, providing pure and quantifiably complete samples for follow-up studies.

• Journal Article Type: Article
• Acceptance Date: May 26, 2023
• Online Publication Date: Jun 7, 2023
• Publication Date: Aug 1, 2023
• Deposit Date: Jun 10, 2023
• Publicly Available Date: Jun 14, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press (OUP)
• Peer Reviewed: Peer Reviewed
• Volume: 523
• Issue: 3
• Pages: 4413–4430
• DOI: https://doi.org/10.1093/mnras/stad1680
• Keywords: Gravitational lensing: strong
• Public URL: https://nottingham-repository.worktribe.com/output/21646556
• Publisher URL: https://academic.oup.com/mnras/article/523/3/4413/7191857?login=false