The COSMOS-Web Lens Survey (COWLS) II: Depth, resolution, and NIR coverage from <i>JWST</i> reveals 17 spectacular lenses
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.
Authors
- Qiuhan He (ORCID: https://orcid.org/0000-0003-3672-9365)
- Louise Paquereau (ORCID: https://orcid.org/0000-0003-2397-0360)
- Guillaume Mahler (ORCID: https://orcid.org/0000-0003-3266-2001)
- Marko Shuntov (ORCID: https://orcid.org/0000-0002-7087-0701)
- Hollis B. Akins (ORCID: https://orcid.org/0000-0003-3596-8794)
- G. Gozaliasl (ORCID: https://orcid.org/0000-0002-0236-919X)
- Shuowen Jin
- Jorge A. Zavala (ORCID: https://orcid.org/0000-0002-7051-1100)
- R. Massey (ORCID: https://orcid.org/0000-0002-6085-3780)
- H. J. McCracken (ORCID: https://orcid.org/0000-0002-9489-7765)
- J.W Nightingale (ORCID: https://orcid.org/0000-0002-8987-7401)
- E. Berman (ORCID: https://orcid.org/0000-0002-8494-3123)
- Nicole E. Drakos (ORCID: https://orcid.org/0000-0003-4761-2197)
- Anton M. Koekemoer (ORCID: https://orcid.org/0000-0002-6610-2048)
- Maximilian von Wietersheim-Kramsta (ORCID: https://orcid.org/0000-0003-4986-5091)
- Caitlin M. Casey (ORCID: https://orcid.org/0000-0002-0930-6466)
- O. Ilbert (ORCID: https://orcid.org/0000-0002-7303-4397)
- Wilfried Mercier (ORCID: https://orcid.org/0000-0001-6865-499X)
- G. Magdis (ORCID: https://orcid.org/0000-0002-4872-2294)
- Diana Scognamiglio (ORCID: https://orcid.org/0000-0001-8450-7885)
- Maximilien Franco (ORCID: https://orcid.org/0000-0002-3560-8599)
- Jason Rhodes (ORCID: https://orcid.org/0000-0002-4485-8549)
- Brant E. Robertson (ORCID: https://orcid.org/0000-0002-4271-0364)
- Natalie B Hogg (ORCID: https://orcid.org/0000-0001-9346-4477)
- Sune Toft (ORCID: https://orcid.org/0000-0003-3631-7176)
- Jeyhan S. Kartaltepe (ORCID: https://orcid.org/0000-0001-9187-3605)
- Daizhong Liu (ORCID: https://orcid.org/0000-0001-9773-7479)
- Andreas L. Faisst (ORCID: https://orcid.org/0000-0002-9382-9832)
- Jacqueline McCleary (ORCID: https://orcid.org/0000-0002-9883-7460)
- Natalie Allen (ORCID: https://orcid.org/0000-0001-9610-7950)
Institutions
- California Institute of Technology (US)
- University of Copenhagen (DK)
- Northeastern University (US)
- Centre National de la Recherche Scientifique (FR)
- Space Telescope Science Institute (US)
- Jet Propulsion Laboratory (US)
- University of Helsinki (FI)
- University of California, Santa Barbara (US)
- Rochester Institute of Technology (US)
- University of Liège (BE)
- University of California, Santa Cruz (US)
- Durham University (GB)
- Helsinki Institute of Physics (FI)
- Institut d'Astrophysique de Paris (FR)
- Purple Mountain Observatory (CN)
- University of Hawaii at Hilo (US)
- Sorbonne Université (FR)
- Laboratoire Univers et Particules de Montpellier (FR)
- Laboratoire d’Astrophysique de Marseille (FR)
- DAWN Center for Independent Living (US)
- Université Bourgogne Franche-Comté (FR)
- National Astronomical Observatory of Japan (JP)
- Infrared Processing and Analysis Center (US)
- Newcastle University (GB)
- The University of Texas at Austin (US)
- Technical University of Denmark (DK)
- Aalto University (FI)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society Letters
- Published
- 2025-08-14
- DOI
- https://doi.org/10.1093/mnrasl/slaf088
- Citations
- 3
- Primary Topic
- Infrared Target Detection Methodologies
- Type
- article
- Field-Weighted Citation Impact
- 14.98
Funders
- National Aeronautics and Space Administration
- California Institute of Technology
- Villum Fonden
- 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