The COSMOS-Web Lens Survey (COWLS) II: Depth, resolution, and NIR coverage from JWST reveals 17 spectacular lenses

Year: 2025

Type: article

Abstract: ABSTRACT The COSMOS-Web Lens Survey (COWLS) presents the first systematic search for strong gravitational lenses in the COSMOS-Web field using data from the James Webb Space Telescope (JWST). Using high-resolution NIRCam imaging, we visually inspected over 42 660 galaxies and identified over 400 lensing candidates. Here, we report the 17 most obvious and spectacular strong lensing systems, distinguished by large Einstein rings, arcs, and distinct lens and source colours. These diverse lenses, identified only through visual inspection of lens-light-subtracted images, represent the extremes of lens parameter space. Exceptionally high signal-to-noise, multiwavelength imaging enables unprecedented lensing analysis, including ‘HST-dark’ source galaxies that are also invisible in deeper but bluer JWST wavebands: enabling clean deblending between the lens and the source. Some sources exhibit dramatic morphological changes across wavelengths, and patterns of dust absorption within lenses. No other current facility, including the Hubble Space Telescope, can discover or image such lenses with comparable detail. We estimate that JWST uncovers a new spectacular lens approximately every 10 to 12 NIRCam pointings, suggesting that over 40 similar lenses remain undiscovered within its first three years of observations. All COWLS data are publicly available on GitHub.

Source: Monthly Notices of the Royal Astronomical Society Letters

DOI: 10.1093/mnrasl/slaf088

Institutions: University of Liège, Durham University, Newcastle University, Centre National de la Recherche Scientifique, Université de Montpellier, Laboratoire Univers et Particules de Montpellier, University of Helsinki, Aalto University, Northeastern University, The University of Texas at Austin, Chinese Academy of Sciences, Purple Mountain Observatory, Aix-Marseille Université, Laboratoire d’Astrophysique de Marseille, California Institute of Technology, Jet Propulsion Laboratory, University of Copenhagen, Institut d'Astrophysique de Paris, Sorbonne Université, University of California, Santa Barbara, Rochester Institute of Technology, Space Telescope Science Institute, University of California, Santa Cruz, National Astronomical Observatory of Japan, University of Hawaii System, University of Hawaii at Hilo, Infrared Processing and Analysis Center, DTU Space, Technical University of Denmark

Language: English

Topic: Galaxies: Formation, Evolution, Phenomena

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $1,451

Funders: Centre national d'études spatiales, National Aeronautics and Space Administration, California Institute of Technology, Villum Fonden, UK Space Agency, Space Telescope Science Institute, UK Research and Innovation, Durham University, Agence Nationale de la Recherche, Centre National d’Etudes Spatiales, Jet Propulsion Laboratory, Science and Technology Facilities Council, H2020 European Research Council

OpenAlex ID: W4414370608