<i>Euclid</i>: A complete Einstein ring in NGC 6505
We report the discovery of a complete Einstein ring around the elliptical galaxy NGC 6505, at z = 0.042. This is the first strong gravitational lens discovered in Euclid and the first in an NGC object from any survey. The combination of the low redshift of the lens galaxy, the brightness of the source galaxy ( I E = 18.1 lensed, I E = 21.3 unlensed), and the completeness of the ring make this an exceptionally rare strong lens, unidentified until its observation by Euclid . We present deep imaging data of the lens from the Euclid Visible Camera (VIS) and Near-Infrared Spectrometer and Photometer (NISP) instruments, as well as resolved spectroscopy from the Keck Cosmic Web Imager (KCWI). The Euclid imaging in particular presents one of the highest signal-to-noise ratio optical/near-infrared observations of a strong gravitational lens to date. From the KCWI data we measure a source redshift of z = 0.406. Using data from the Dark Energy Spectroscopic Instrument (DESI) we measure a velocity dispersion for the lens galaxy of σ ⋆ = 303 ± 15 km s −1 . We model the lens galaxy light in detail, revealing angular structure that varies inside the Einstein ring. After subtracting this light model from the VIS observation, we model the strongly lensed images, finding an Einstein radius of 2.″5, corresponding to 2.1 kpc at the redshift of the lens. This is small compared to the effective radius of the galaxy, R eff ∼ 12.″3. Combining the strong lensing measurements with analysis of the spectroscopic data we estimate a dark matter fraction inside the Einstein radius of f DM = (11.1 −3.5 +5.4 )% and a stellar initial mass-function (IMF) mismatch parameter of α IMF = 1.26 −0.08 +0.05 , indicating a heavier-than-Chabrier IMF in the centre of the galaxy.
Authors
- Dominique Sluse (ORCID: https://orcid.org/0000-0001-6116-2095)
- G. Seidel (ORCID: https://orcid.org/0000-0003-2907-353X)
- J. Brinchmann (ORCID: https://orcid.org/0000-0003-4359-8797)
- Will J. Percival (ORCID: https://orcid.org/0000-0002-0644-5727)
- G. Mainetti (ORCID: https://orcid.org/0000-0003-2384-2377)
- R. P. Saglia
- P. Tallada-Crespí (ORCID: https://orcid.org/0000-0002-1336-8328)
- O. Lahav (ORCID: https://orcid.org/0000-0002-1134-9035)
- G. Riccio (ORCID: https://orcid.org/0000-0001-7020-1172)
- L. Conversi
- D. Le Mignant (ORCID: https://orcid.org/0000-0002-5339-5515)
- C. Sirignano
- M. Brescia (ORCID: https://orcid.org/0000-0001-9506-5680)
- R. Laureijs
- E. Merlin (ORCID: https://orcid.org/0000-0001-6870-8900)
- I. Hook (ORCID: https://orcid.org/0000-0002-2960-978X)
- M. Vaccari (ORCID: https://orcid.org/0000-0002-6748-0577)
- M. Kunz
- C. Baccigalupi (ORCID: https://orcid.org/0000-0002-8211-1630)
- J. Carretero (ORCID: https://orcid.org/0000-0002-3130-0204)
- M. Schirmer (ORCID: https://orcid.org/0000-0003-2568-9994)
- J. Steinwagner
- F. Marulli (ORCID: https://orcid.org/0000-0002-8850-0303)
- Yuguang Chen (ORCID: https://orcid.org/0000-0003-4520-5395)
- Devon Powell (ORCID: https://orcid.org/0000-0002-4912-9943)
- C. Giocoli (ORCID: https://orcid.org/0000-0002-9590-7961)
- O. Marggraf (ORCID: https://orcid.org/0000-0001-7242-3852)
- F. Courbin (ORCID: https://orcid.org/0000-0003-0758-6510)
- Y. Copin
- A. Kiessling (ORCID: https://orcid.org/0000-0002-2590-1273)
- Santiago Casas (ORCID: https://orcid.org/0000-0002-4751-5138)
- A. Grazian (ORCID: https://orcid.org/0000-0002-5688-0663)
- M. Jhabvala
- F. Torradeflot (ORCID: https://orcid.org/0000-0003-1160-1517)
- G. Sirri (ORCID: https://orcid.org/0000-0003-2626-2853)
- S. Mei (ORCID: https://orcid.org/0000-0002-2849-559X)
- S. Bardelli (ORCID: https://orcid.org/0000-0002-8900-0298)
- Mathilde Jauzac (ORCID: https://orcid.org/0000-0003-1974-8732)
- F Faustini
- Francisco Javier Castander (ORCID: https://orcid.org/0000-0001-7316-4573)
- M. Martinelli (ORCID: https://orcid.org/0000-0002-6943-7732)
- Alberto Basset (ORCID: https://orcid.org/0000-0002-3603-9316)
- A. Amara
- V. Capobianco
- L. Moscardini (ORCID: https://orcid.org/0000-0002-3473-6716)
- S.-M Niemi
- T. Schrabback (ORCID: https://orcid.org/0000-0002-6987-7834)
- S. Farrens (ORCID: https://orcid.org/0000-0002-9594-9387)
- Giulia Despali (ORCID: https://orcid.org/0000-0001-6150-4112)
- Hans‐Walter Rix (ORCID: https://orcid.org/0000-0003-4996-9069)
- E. Zucca (ORCID: https://orcid.org/0000-0002-5845-8132)
- S. Andreon (ORCID: https://orcid.org/0000-0002-2041-8784)
- S. Pires (ORCID: https://orcid.org/0000-0002-0249-2104)
- S. V. H. Haugan
- R. Massey (ORCID: https://orcid.org/0000-0002-6085-3780)
- T. Vassallo
- Benjamin Joachimi (ORCID: https://orcid.org/0000-0001-7494-1303)
- S. Paltani (ORCID: https://orcid.org/0000-0002-8108-9179)
- R. Toledo-Moreo
- M. Moresco
- B. R. Granett (ORCID: https://orcid.org/0000-0003-2694-9284)
- D. Sapone (ORCID: https://orcid.org/0000-0001-7089-4503)
- M. Meneghetti (ORCID: https://orcid.org/0000-0003-1225-7084)
- D. Bonino (ORCID: https://orcid.org/0000-0002-3336-9977)
- J.W Nightingale (ORCID: https://orcid.org/0000-0002-8987-7401)
- A. Veropalumbo (ORCID: https://orcid.org/0000-0003-2387-1194)
- G. Congedo (ORCID: https://orcid.org/0000-0003-2508-0046)
- I Lloro (ORCID: https://orcid.org/0000-0001-5966-1434)
- L. Valenziano (ORCID: https://orcid.org/0000-0002-1170-0104)
- A. Caillat
- C Colodro-Conde
- E. Romelli (ORCID: https://orcid.org/0000-0003-3069-9222)
- C. Burigana (ORCID: https://orcid.org/0000-0002-3005-5796)
- A. M. Di Giorgio (ORCID: https://orcid.org/0000-0002-4767-2360)
- Christopher J. Conselice (ORCID: https://orcid.org/0000-0003-1949-7638)
- Henk Hoekstra (ORCID: https://orcid.org/0000-0002-0641-3231)
- I. Tutusaus (ORCID: https://orcid.org/0000-0002-3199-0399)
- H. Degaudenzi (ORCID: https://orcid.org/0000-0002-5887-6799)
- O. Mansutti
- G. Zamorani (ORCID: https://orcid.org/0000-0002-2318-301X)
- Matteo Viel (ORCID: https://orcid.org/0000-0002-2642-5707)
- N. Martinet (ORCID: https://orcid.org/0000-0003-2786-7790)
- G. Vernardos (ORCID: https://orcid.org/0000-0001-8554-7248)
- Rachana Bhatawdekar (ORCID: https://orcid.org/0000-0003-0883-2226)
- W. Gillard (ORCID: https://orcid.org/0000-0003-4744-9748)
- R. Kohley
- J.A. Acevedo Barroso (ORCID: https://orcid.org/0000-0002-9654-1711)
- C. Padilla Aranda (ORCID: https://orcid.org/0000-0001-7951-0166)
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- S. Rhoades
- M. Roncarelli (ORCID: https://orcid.org/0000-0001-9587-7822)
- F. Dubath (ORCID: https://orcid.org/0000-0002-6533-2810)
- R. B. Metcalf (ORCID: https://orcid.org/0000-0003-3167-2574)
- A. Hornstrup (ORCID: https://orcid.org/0000-0002-3363-0936)
- E. Medinaceli (ORCID: https://orcid.org/0000-0002-4040-7783)
- C. Tortora (ORCID: https://orcid.org/0000-0001-7958-6531)
- A. Balestra (ORCID: https://orcid.org/0000-0002-6967-261X)
- K. Jahnkę (ORCID: https://orcid.org/0000-0003-3804-2137)
- B. Altieri (ORCID: https://orcid.org/0000-0003-3936-0284)
- A. Secroun
- M. Farina (ORCID: https://orcid.org/0000-0002-3089-7846)
- R. Bender (ORCID: https://orcid.org/0000-0001-7179-0626)
- F. Pasian (ORCID: https://orcid.org/0000-0002-4869-3227)
- L. Guzzo
- C.A.J Duncan
- F. Hormuth
- Stephen Serjeant (ORCID: https://orcid.org/0000-0002-0517-7943)
- J. Weller (ORCID: https://orcid.org/0000-0002-8282-2010)
- S. Ligori (ORCID: https://orcid.org/0000-0003-4172-4606)
- M. Castellano (ORCID: https://orcid.org/0000-0001-9875-8263)
- Angelos Nersesian (ORCID: https://orcid.org/0000-0001-6843-409X)
- A. Zacchei (ORCID: https://orcid.org/0000-0003-0396-1192)
- S. Galeotta
- F. Raison (ORCID: https://orcid.org/0000-0002-7819-6918)
- E. Franceschi
- Marco Baldi (ORCID: https://orcid.org/0000-0003-4145-1943)
- P. Gómez-Álvarez (ORCID: https://orcid.org/0000-0002-8594-5358)
- Ariel G. Sánchez (ORCID: https://orcid.org/0000-0003-1198-831X)
- S. Dusini (ORCID: https://orcid.org/0000-0002-1128-0664)
- Thomas E. Collett (ORCID: https://orcid.org/0000-0001-5564-3140)
- K. Markovič
- I.T Andika (ORCID: https://orcid.org/0000-0001-6102-9526)
- Mike Walmsley (ORCID: https://orcid.org/0000-0002-6408-4181)
- S. Camera (ORCID: https://orcid.org/0000-0003-3399-3574)
- Z. Sakr
- Lindsay Oldham (ORCID: https://orcid.org/0000-0002-6890-0123)
- Asantha Cooray
- M. Kilbinger (ORCID: https://orcid.org/0000-0001-9513-7138)
- R. Gavazzi (ORCID: https://orcid.org/0000-0002-5540-6935)
- J. Dinis (ORCID: https://orcid.org/0000-0001-5075-1601)
- V. Lindholm
- Jason Rhodes (ORCID: https://orcid.org/0000-0002-4485-8549)
- H. Dannerbauer (ORCID: https://orcid.org/0000-0001-7147-3575)
- G. Verdoes Kleijn (ORCID: https://orcid.org/0000-0001-5803-2580)
- M. Cropper (ORCID: https://orcid.org/0000-0003-4571-9468)
- R. Nakajima
- E. Keihänen (ORCID: https://orcid.org/0000-0003-1804-7715)
- B. Sartoris
- G. Castignani (ORCID: https://orcid.org/0000-0001-6831-0687)
- S. Cavuoti (ORCID: https://orcid.org/0000-0002-3787-4196)
- N. Auricchio (ORCID: https://orcid.org/0000-0003-4444-8651)
- M. Frailis (ORCID: https://orcid.org/0000-0002-7400-2135)
- M. Fumana
- Conor M. O’Riordan (ORCID: https://orcid.org/0000-0003-2227-1998)
- Petra Schneider (ORCID: https://orcid.org/0000-0001-8561-2679)
- C. Carbone
- S. Kermiche
- L. Corcione (ORCID: https://orcid.org/0000-0002-6497-5881)
- W. Holmes
- J. M. Diego (ORCID: https://orcid.org/0000-0001-9065-3926)
- V. Pettorino
- P. B. Lilje
- M Melchior
- S. Serrano (ORCID: https://orcid.org/0000-0002-0211-2861)
- G. Polenta (ORCID: https://orcid.org/0000-0003-4067-9196)
- B. Rusholme (ORCID: https://orcid.org/0000-0001-7648-4142)
- E. Rossetti (ORCID: https://orcid.org/0000-0003-0238-4047)
- Tucker Jones (ORCID: https://orcid.org/0000-0001-5860-3419)
- A. Galan (ORCID: https://orcid.org/0000-0003-2547-9815)
- E. Branchini (ORCID: https://orcid.org/0000-0002-0808-6908)
- L. Pozzetti (ORCID: https://orcid.org/0000-0001-7085-0412)
- G. De Lucia (ORCID: https://orcid.org/0000-0002-6220-9104)
- H. M. Courtois (ORCID: https://orcid.org/0000-0003-0509-1776)
- R. C. Nichol (ORCID: https://orcid.org/0000-0003-0939-6518)
- P Casenove
- Tian Li (ORCID: https://orcid.org/0009-0005-5008-0381)
- Yun Wang (ORCID: https://orcid.org/0000-0002-4749-2984)
- A. Da Silva (ORCID: https://orcid.org/0000-0002-6385-1609)
- L. Stančo (ORCID: https://orcid.org/0000-0002-9706-5104)
- G. Meylan
- C. Adami (ORCID: https://orcid.org/0000-0002-8904-3925)
- P. Hudelot
- V. Scottez
- Y. Mellier
- L. Popa
- I. Tereno (ORCID: https://orcid.org/0000-0002-4537-6218)
- R. Rebolo
- L.R Ecker
- P Battaglia
- K. Pedersen
- Benjamin Clément (ORCID: https://orcid.org/0000-0002-7966-3661)
- M. Kümmel
- H. Kurki‐Suonio
- M. Poncet
- B. Kubik (ORCID: https://orcid.org/0009-0006-5823-4880)
- S. Vegetti
- N. Fourmanoit
- A Cimatti
- A. Mora
- A. Renzi
- K. G. C. Vasan
- L. Leuzzi (ORCID: https://orcid.org/0009-0006-4479-7017)
Institutions
- Université Claude Bernard Lyon 1 (FR)
- University of Geneva (CH)
- Institució Catalana de Recerca i Estudis Avançats (ES)
- Leiden University (NL)
- California Institute of Technology (US)
- University of Copenhagen (DK)
- Centre National de la Recherche Scientifique (FR)
- Goddard Space Flight Center (US)
- Institute of Space Sciences (ES)
- Jet Propulsion Laboratory (US)
- University of Helsinki (FI)
- American Museum of Natural History (US)
- Université Toulouse III - Paul Sabatier (FR)
- Consejo Superior de Investigaciones Científicas (ES)
- University of Bonn (DE)
- Scuola Internazionale Superiore di Studi Avanzati (IT)
- University of Padua (IT)
- University of Lisbon (PT)
- University of Trieste (IT)
- University of Waterloo (CA)
- University of Cape Town (ZA)
- Universidad de La Laguna (ES)
- Lehman College (US)
- University of Groningen (NL)
- Université Fédérale de Toulouse Midi-Pyrénées (FR)
- Université Catholique de Lille (FR)
- Universidade do Porto (PT)
- Perimeter Institute (CA)
- Saint Joseph University (LB)
- University of Oslo (NO)
- University of Toronto (CA)
- Institute for High Energy Physics (ES)
- University of Milan (IT)
- Durham University (GB)
- Universität Innsbruck (AT)
- The Open University (GB)
- University of California, Irvine (US)
- Université Paris Cité (FR)
- Aix-Marseille Université (FR)
- Heidelberg University (DE)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- Centre National d'Études Spatiales (FR)
- Helsinki Institute of Physics (FI)
- Astronomical Observatory of Rome (IT)
- Agenzia Spaziale Italiana (IT)
- Trieste Astronomical Observatory (IT)
- Institut d'Astrophysique de Paris (FR)
- Astronomical Observatory of Capodimonte (IT)
- Laboratoire AstroParticule et Cosmologie (FR)
- Brera Astronomical Observatory (IT)
- University of Surrey (GB)
- University of Manchester (GB)
- FHNW University of Applied Sciences and Arts Northwestern Switzerland (CH)
- Institute for High Performance Computing and Networking (IT)
- Universidad Politécnica de Cartagena (ES)
- Ghent University (BE)
- Sorbonne Université (FR)
- Técnicas Reunidas (Spain) (ES)
- Astrophysique, Instrumentation et Modélisation (FR)
- Institute of Astrophysics and Space Sciences (PT)
- Max Planck Institute for Extraterrestrial Physics (DE)
- Institut d'Estudis Espacials de Catalunya (ES)
- European Space Astronomy Centre (ES)
- Istituto Nazionale di Fisica Nucleare, Sezione di Torino (IT)
- Institute for Space Astrophysics and Planetology (IT)
- Max Planck Institute for Astrophysics (DE)
- Istituto Nazionale di Fisica Nucleare, Sezione di Padova (IT)
- Osservatorio Astrofisico di Torino (IT)
- Royal Observatory (GB)
- Istituto Nazionale di Fisica Nucleare, Sezione di Napoli (IT)
- Max Planck Institute for Astronomy (DE)
- Istituto di Radioastronomia di Bologna (IT)
- Unidades Centrales Científico-Técnicas (ES)
- Istituto Nazionale di Fisica Nucleare, Sezione di Genova (IT)
- CEA Paris-Saclay (FR)
- Instituto de Astrofísica de Canarias (ES)
- Institut National de Physique Nucléaire et de Physique des Particules (FR)
- Institute of Space Science - INFLPR Subsidiary (RO)
- Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules (FR)
- Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (IT)
- Port d'Informació Científica (ES)
- Istituto Nazionale di Fisica Nucleare, Sezione di Trieste (IT)
- Institute for Fundamental Physics of the Universe (IT)
- Instituto de Física de Cantabria (ES)
- Istituto Nazionale di Fisica Nucleare, Sezione di Roma I (IT)
- Osservatorio Astronomico di Padova (IT)
- European Space Research Institute (IT)
- Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (ES)
- Institut de Recherche en Astrophysique et Planétologie (FR)
- Infrared Processing and Analysis Center (US)
- Osservatorio di Astrofisica e Scienza dello Spazio
- Fondazione ICSC Centro Nazionale di Ricerca in High Performance Computing, Big Data e Quantum Computing
- Inter-university Institute for Data Intensive Astronomy (ZA)
- European Space Research and Technology Centre (NL)
- University College London (GB)
- École Polytechnique Fédérale de Lausanne (CH)
- University of Turin (IT)
- Technical University of Munich (DE)
- University of Portsmouth (GB)
- Lancaster University (GB)
- University of Chile (CL)
- Heidelberg Institute for Theoretical Studies (DE)
- Universitat de Barcelona (ES)
- Ludwig-Maximilians-Universität München (DE)
- University of Genoa (IT)
- University of California, Davis (US)
- Newcastle University (GB)
- University of the Western Cape (ZA)
- National Institute for Astrophysics (IT)
- RWTH Aachen University (DE)
- Netherlands Institute for Radio Astronomy (NL)
- University of Bologna (IT)
- University of KwaZulu-Natal (ZA)
- Universitat Politècnica de Catalunya (ES)
- Technical University of Denmark (DK)
- University of Edinburgh (GB)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2025-02-01
- DOI
- https://doi.org/10.1051/0004-6361/202453014
- Citations
- 11
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 12.70
Funders
- National Science Foundation
- U.S. Department of Energy
- National Aeronautics and Space Administration
- W. M. Keck Foundation
- Gordon and Betty Moore Foundation
- California Institute of Technology
- European Space Agency
- European Commission
- Belgian Federal Science Policy Office
- Consejo Nacional de Ciencia y Tecnología
- Magyar Tudományos Akadémia
- Agenzia Spaziale Italiana
- Max-Planck-Gesellschaft
- Centre National de la Recherche Scientifique
- Ministerio de Ciencia e Innovación
- National Astronomical Observatory of Japan
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives
- Agenția Spațială Română
- Norsk Romsenter
- Office of Science
- Science and Technology Facilities Council
- Fundação para a Ciência e a Tecnologia
- Division of Astronomical Sciences
- Lawrence Berkeley National Laboratory