Euclid DR1 Strong Lens Catalogue (ECLIPSE)

This record contains the Euclid Lens Identification Pipeline and Scientific Exploration (ECLIPSE) results from Euclid Data Release 1 (DR1). We share the catalogue together with the search information, lens models, deflector photometric redshifts and SED fits, and images for every catalogued system.

The search for galaxy-galaxy strong gravitational lenses covered approximately 2000 deg2 of Euclid DR1 data. Around 68 million galaxies were scored by five machine-learning networks, the most promising candidates were classified by citizen scientists on Space Warps (Zooniverse), and over 26 000 systems were graded by expert inspectors. The final catalogue contains the 26 662 unique objects assigned grades by the experts: 6073 grade A ('sure lens'), 8999 grade B ('probable lens'), 9010 grade C ('possible lens') and 2580 grade X ('not a lens'). The 15 072 grade A and B systems were modelled automatically with PyAutoLens, and their deflector galaxies were characterised with photometric redshifts and SED fitting.

Contents

• ECLIPSE_object_catalogue.zip: The main catalogue from ECLIPSE-A and the starting point for most users. Contains ECLIPSE_object_catalogue.csv which includes one row per unique system graded by the experts (26 662 rows), comprising 6073 grade A (sure lens), 8999 grade B (probable lens), 9010 grade C (possible lens), and 2580 grade X (not a lens) systems. For each system it gives coordinates, Euclid DR1 designation, expert grade and score, machine-learning and Space Warps scores, search-stage flags, previous publications, DESI deflector redshifts, and flags for disc deflectors and large systems. Columns are described in the README file within.

• ECLIPSE_cutout_catalogue.zip: The classification scores for all cutouts in the ECLIPSE DR1 search, from ECLIPSE-B. One row per search cutout (67 609 627) within the DR1 area we searched (excluding Q1 area and deep fields). It gives the scores from the five networks and the ensemble, the Space Warps Classify and Refine scores, flags recording whether each cutout was selected for and seen at each stage of the search, the highest expert grade of any object in the cutout, and the random and calibration samples used to measure the completeness of the search. The cutouts have not been deduplicated, and therefore some lenses necessarily appear more than once, in different cutouts. Columns are described in the README file within.

• ECLIPSE_lens_models.zip: Catalogue-level results from the ECLIPSE-C PyAutoLens lens models of the grade A and B systems. The tables are in catalogue_csvs.zip (within this zip); the main one is csv/dr1_catalogue_15072_master.csv, with one row per system (15 072 rows), keyed by unique_identifier (the same as Unique_Identifier in the object catalogue). Start with README.md within catalogue_csvs.zip, which describes the release and points to the table descriptions and known issues.

• catalogue_part_01.zip to catalogue_part_20.zip: Per-lens products from the PyAutoLens models from ECLIPSE-C. Each folder contains the 10"x10" multi-band cutout used for modelling (image, PSF and noise map), segmentation maps, the lens and source model images, mass maps, and fit figures. See the README in ECLIPSE_lens_models.zip for details; in particular parts_manifest.csv in ECLIPSE_lens_models.zip lists which part holds each lens. If you just want the raw FITS data, look here.

• ECLIPSE_D_dr1_redshifts_and_physical_properties.zip: Photometric redshifts and stellar-population properties of the deflector galaxies of the grade A and B systems, from ECLIPSE-D. One row per system (15 072 rows), with Phosphoros photometric redshifts and Prospector SED-fitting results (stellar mass, star-formation rate, ages, and metallicity). A shorter version with the most-used columns is also provided. Columns and quality flags are described in the README files within.

• colour_images.zip: Colour images of every catalogued system: 6073 grade A, 8999 grade B, 9010 grade C, and 2580 grade X. One 10"x10" JPEG per system (100 x 100 pixels, 0.1" per pixel, north up, east left, and centred on the catalogue position). Note that ECLIPSE_object_catalogue.csv contains large_system_warning to flag systems where lensing features may extend beyond the default 10"x10" cutout.

• strong_lensing_collage.png, Euclid_spacecraft_strong_lens_mosaic.jpg, and ECLIPSE_grade_AB_mosaic.jpg show collages of the ECLIPSE strong lenses. strong_lensing_collage.png shows some highlighted systems discussed in detail in ECLIPSE-A, Euclid_spacecraft_strong_lens_mosaic.jpg is a photomosaic of the Euclid spacecraft built from 14,400 grade A+B+C systems in the ECLIPSE sample, and ECLIPSE_grade_AB_mosaic.jpg is a mosaic of all the grade A+B systems from ECLIPSE.

The individual lenses and their lens models can be browsed interactively at https://euclid-eclipse-lenses.org, where the lens-modelling data for individual systems can also be downloaded.

Papers

Please cite the relevant papers used in this release:

• ECLIPSE-A: Strong lens catalogue overview - Euclid Collaboration: Lines, N. E. P., Holloway, P., Li, T., et al. 2026
• ECLIPSE-B: Discovery pipeline overview - Euclid Collaboration: Holloway, P., Verma, A., Lines, N., et al. 2026
• ECLIPSE-C: Lens modelling pipeline overview - Euclid Collaboration: Nightingale, J., Vincken, S., Ecker, L., et al. 2026
• ECLIPSE-D: Photometric redshifts and stellar properties of DR1 strong lenses - Euclid Collaboration: Nersesian, A., Nightingale, J., Sluse, D., et al. 2026

The Euclid DR1 data are available at https://www.cosmos.esa.int/web/euclid/data-release-dr1.