The COSMOS-Web Lens Survey (COWLS) III: forecasts versus data
Abstract
We compare forecasts for the abundance and properties of strong gravitational lenses in the COSMOS-Web survey, a $0.54$ deg2 survey of the COSMOS field using the NIRCam and MIRI instruments aboard JWST, with the first catalogue of strong lens candidates identified in the observed NIRCam data, COWLS. We modify the lenspop package to produce a forecast for strong lensing in COSMOS-Web. We add a new mock galaxy catalogue to use as the source population, as well as the COSMOS-Web survey specifications, including the transmission data for the four NIRCam filters used. We forecast 107 strong lenses can be detected in COSMOS-Web across all bands, assuming complete subtraction of the lens galaxy light. The majority of the lenses are forecast to have small Einstein radii (θE < 1 arcsecond) and lie at redshifts between 0 < z <2, whilst the source redshift distribution peaks at z∼ 3 and has a long tail extending up to z ∼ 11, unambiguously showing that strong lensing in JWST can probe the entirety of the epoch of reionisation. We compare our forecast with the distributions of Einstein radii, lens photometric redshifts, and lens and source magnitudes in the observed lenses, finding that whilst the forecast and observed Einstein radii distributions match, the redshifts and magnitudes do not. The observed lens redshift distribution peaks at a slightly lower redshift than the forecast one, whilst the lens magnitudes are systematically brighter in the observed data than in the forecast. Assuming the validity of the lenspop forecast, this finding motivates further inspection of the COWLS data to search for the as-yet undiscovered population of faint, high-redshift lenses.
Related
- Evolution of the morphology-density and morphology-mass relations of quiescent galaxies at 0.5 {2}lt;z<$ 2.5 in the COSMOS-Web survey
- The NIKA2 Cosmological Legacy Survey in COSMOS: Final 1.2,mm and 2,mm source catalogs and redshift distribution of dusty star-forming galaxies
- X-ray to Mid-IR Spectral Energy Distributions: A Catalog of X-ray Selected AGNs in the XMM-COSMOS Survey
- The GMRT CATz1-COSMOS Survey: HI 21 cm emission from star-forming galaxies at z≈1 in the COSMOS field
- Cosmic Evolution Survey: LOFAR 144 MHz imaging of the COSMOS field
BibTeX
@article{hogg2026cosmosweb,
title = {{The COSMOS-Web Lens Survey (COWLS) III: forecasts versus data}},
author = {Natalie B Hogg and James W Nightingale and Quihan He and Jacqueline Mccleary and Guillaume Mahler and Aristeidis Amvrosiadis and Ghassem Gozaliasl and Edward Berman and Richard J Massey and Diana Scognamiglio and Maximilien Franco and Daizhong Liu and Marko Shuntov and Louise Paquereau and Olivier Ilbert and Natalie Allen and Sune Toft and Hollis B Akins and Caitlin M Casey and Jeyhan S Kartaltepe and Anton M Koekemoer and Henry Joy Mccracken and Jason D Rhodes and Brant E Robertson and Nicole E Drakos and Andreas L Faisst and Hossein Hatamnia and Sophie L Newman},
journal = {Monthly Notices of the Royal Astronomical Society},
year = {2026},
month = oct,
doi = {10.1093/mnras/staf1678},
eprint = {2503.08785},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05007890v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The COSMOS-Web Lens Survey (COWLS) III: forecasts versus data
AU - Natalie B Hogg
AU - James W Nightingale
AU - Quihan He
AU - Jacqueline Mccleary
AU - Guillaume Mahler
AU - Aristeidis Amvrosiadis
AU - Ghassem Gozaliasl
AU - Edward Berman
AU - Richard J Massey
AU - Diana Scognamiglio
AU - Maximilien Franco
AU - Daizhong Liu
AU - Marko Shuntov
AU - Louise Paquereau
AU - Olivier Ilbert
AU - Natalie Allen
AU - Sune Toft
AU - Hollis B Akins
AU - Caitlin M Casey
AU - Jeyhan S Kartaltepe
AU - Anton M Koekemoer
AU - Henry Joy Mccracken
AU - Jason D Rhodes
AU - Brant E Robertson
AU - Nicole E Drakos
AU - Andreas L Faisst
AU - Hossein Hatamnia
AU - Sophie L Newman
PY - 2026
DA - 2026/10/09
JO - Monthly Notices of the Royal Astronomical Society
DO - 10.1093/mnras/staf1678
UR - https://hal.science/hal-05007890v1
AB - We compare forecasts for the abundance and properties of strong gravitational lenses in the COSMOS-Web survey, a $0.54$ deg^2 survey of the COSMOS field using the NIRCam and MIRI instruments aboard JWST, with the first catalogue of strong lens candidates identified in the observed NIRCam data, COWLS. We modify the lenspop package to produce a forecast for strong lensing in COSMOS-Web. We add a new mock galaxy catalogue to use as the source population, as well as the COSMOS-Web survey specifications, including the transmission data for the four NIRCam filters used. We forecast 107 strong lenses can be detected in COSMOS-Web across all bands, assuming complete subtraction of the lens galaxy light. The majority of the lenses are forecast to have small Einstein radii (θ_E < 1 arcsecond) and lie at redshifts between 0 < z <2, whilst the source redshift distribution peaks at z∼ 3 and has a long tail extending up to z ∼ 11, unambiguously showing that strong lensing in JWST can probe the entirety of the epoch of reionisation. We compare our forecast with the distributions of Einstein radii, lens photometric redshifts, and lens and source magnitudes in the observed lenses, finding that whilst the forecast and observed Einstein radii distributions match, the redshifts and magnitudes do not. The observed lens redshift distribution peaks at a slightly lower redshift than the forecast one, whilst the lens magnitudes are systematically brighter in the observed data than in the forecast. Assuming the validity of the lenspop forecast, this finding motivates further inspection of the COWLS data to search for the as-yet undiscovered population of faint, high-redshift lenses.
SN - 0035-8711
SN - 1365-2966
ER -