Euclid: The Early Release Observations Lens Search Experiment

Abstract

We investigated the ability of the Euclid telescope to detect galaxy-scale gravitational lenses. To do so, we performed a systematic visual inspection of the $0.7{\mathrm{deg}}^2$ Euclid Early Release Observations data towards the Perseus cluster using both the high-resolution $I_{\mathrm{E}}$ band and the lower-resolution $Y_{\mathrm{E}}$, $J_{\mathrm{E}}$, $H_{\mathrm{E}}$ bands. Each extended source brighter than magnitude 23 in $I_{\mathrm{E}}$ was inspected by 41 expert human classifiers. This amounts to $12086$ stamps of $10^{\prime \prime }\times 10^{\prime \prime }$. We found $3$ grade A and $13$ grade B candidates. We assessed the validity of these $16$ candidates by modelling them and checking that they are consistent with a single source lensed by a plausible mass distribution. Five of the candidates pass this check, five others are rejected by the modelling, and six are inconclusive. Extrapolating from the five successfully modelled candidates, we infer that the full $14000{\mathrm{deg}}^2$ of the Euclid Wide Survey should contain $100000_{-30000}^{+70000}$ galaxy-galaxy lenses that are both discoverable through visual inspection and have valid lens models. This is consistent with theoretical forecasts of $170000$ discoverable galaxy-galaxy lenses in Euclid. Our five modelled lenses have Einstein radii in the range $0.{}^{\prime \prime }68<{\theta }_{\mathrm{E}}<1.{}^{\prime \prime }24$, but their Einstein radius distribution is on the higher side when compared to theoretical forecasts. This suggests that our methodology is likely missing small-Einstein-radius systems. Whilst it is implausible to visually inspect the full Euclid dataset, our results corroborate the promise that Euclid will ultimately deliver a sample of around $10^5$ galaxy-scale lenses.

Replacement after peer review. 16 pages, 17 figures, Zenodo appendix at https://zenodo.org/records/14946028

References in corpus (41)

• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• H0LiCOW XIII. A 2.4% measurement of $H_0$ from lensed quasars: $5.3\sigma$ tension between early and late-Universe probes
• Euclid. I. Overview of the Euclid mission
• The population of galaxy-galaxy strong lenses in forthcoming optical imaging surveys
• Detection of a Dark Substructure through Gravitational Imaging
• Bayesian Strong Gravitational-Lens Modeling on Adaptive Grids: Objective Detection of Mass Substructure in Galaxies
• The Sloan Lens ACS Survey. IX. Colors, Lensing and Stellar Masses of Early-type Galaxies
• First catalog of strong lens candidates in the COSMOS field
• ALMA Observations of SPT-Discovered, Strongly Lensed, Dusty, Star-Forming Galaxies
• Low-mass halo perturbations in strong gravitational lenses at redshift z$\sim$0.5 are consistent with CDM
• Space Warps II. New Gravitational Lens Candidates from the CFHTLS Discovered through Citizen Science
• Euclid. III. The NISP Instrument
• The bulge-halo conspiracy in massive elliptical galaxies: implications for the stellar initial mass function and halo response to baryonic processes
• TDCOSMO. XII. Improved Hubble constant measurement from lensing time delays using spatially resolved stellar kinematics of the lens galaxy
• Euclid. II. The VIS Instrument
• Survey of gravitationally-lensed objects in HSC imaging (SuGOHI). III. Statistical strong lensing constraints on the stellar IMF of CMASS galaxies
• Ideas for Citizen Science in Astronomy
• ALMA imaging of SDP.81 - II. A pixelated reconstruction of the CO emission lines
• Strong lens systems search in the Dark Energy Survey using Convolutional Neural Networks
• Mining for Strong Gravitational Lenses with Self-supervised Learning
• Line-of-sight effects in strong lensing: Putting theory into practice
• Cosmography with Supernova Refsdal through time-delay cluster lensing: independent measurements of the Hubble constant and geometry of the Universe
• Line-of-sight effects in strong gravitational lensing
• A novel 3D technique to study the kinematics of lensed galaxies
• Euclid: Early Release Observations -- Programme overview and pipeline for compact- and diffuse-emission photometry
• Constraining the low-mass end of the Initial Mass Function with Gravitational Lensing
• A novel approach to visibility-space modelling of interferometric gravitational lens observations at high angular resolution
• An Atlas of Predicted Exotic Gravitational Lenses
• Gravitational Lenses With More Than Four Images: I. Classification of Caustics
• Strong lensing in UNIONS: Toward a pipeline from discovery to modeling
• A seven square degrees survey for galaxy-scale gravitational lenses with the HST imaging archive
• Sensitivity of strong lensing observations to dark matter substructure: a case study with Euclid
• Hubble Asteroid Hunter: II. Identifying strong gravitational lenses in HST images with crowdsourcing
• Compound lensing: Einstein Zig-Zags and high multiplicity lensed images
• ALMA view of RX J1131-1231: Sub-kpc CO (2-1) mapping of a molecular disk in a lensed star-forming quasar host galaxy
• Euclid: Early Release Observations -- Overview of the Perseus cluster and analysis of its luminosity and stellar mass functions
• The impact of human expert visual inspection on the discovery of strong gravitational lenses
• Cosmic Shear with Einstein Rings
• Measuring line-of-sight shear with Einstein rings: a proof of concept
• HOLISMOKES -- XI. Evaluation of supervised neural networks for strong-lens searches in ground-based imaging surveys
• TEGLIE: Transformer encoders as strong gravitational lens finders in KiDS

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• The COSMOS-Web Lens Survey (COWLS) I: Discovery of >100 high redshift strong lenses in contiguous JWST imaging
• HOLISMOKES XV. Search for strong gravitational lenses combining ground-based and space-based imaging
• The COSMOS-Web Lens Survey (COWLS) II: depth, resolution, and NIR coverage from JWST reveal 17 spectacular lenses
• HOLISMOKES XVI: Lens search in HSC-PDR3 with a neural network committee and post-processing for false-positive removal
• Searching for strong lensing by late-type galaxies in UNIONS
• Parametric strong lensing model of the galaxy cluster Abell 2390 from Euclid and MUSE observations
• Identifying Astrophysical Anomalies in 99.6 Million Cutouts from the Hubble Legacy Archive Using AnomalyMatch
• AnomalyMatch: Discovering Rare Objects of Interest with Semi-supervised and Active Learning
• Identification of gravitational lenses obscured by foreground light in the KiDS dataset using U-Nets and ResNets