Euclid Quick Data Release (Q1)

Astronomy and Astrophysics, vol. 712, pp. A207

Abstract

We present an end-to-end, iterative pipeline for efficient identification of strong galaxy-galaxy lensing systems, applied to the Euclid Q1 imaging data. Starting from the VIS catalogues, we rejected point sources, applied a magnitude cut ( I E ≤ 24) on the deflectors, and ran a pixel-level artefact-and-noise filter to build 96 × 96 pixel cutouts. The VIS+NISP colour composites were constructed with a VIS-anchored luminance scheme that preserves VIS morphology and NISP colour contrast. A VIS-only seed classifier supplies clear positives and typical impostors, which we used to curate a morphology-balanced negative set and augment scarce positives. Among the six compact convolutional neural networks (CNNs) that had been studied initially, the modified VGG16 (GlobalAveragePooling + 256/128 dense layers with the last nine layers trainable) exhibited the best performance. In our run, the training set grew from 27 seed lenses (augmented 67× to 1809) plus 2000 negatives to a colour dataset of 30 686 images. After three rounds of iterative fine-tuning, a human grading of the top 4000 candidates ranked by the final model yielded 441 Grade A/B candidate lensing systems, including 311 overlapping with the existing Q1 strong-lens catalogue, and 130 additional A/B candidates (9 As and 121 Bs) not previously reported. Independently, the model recovered 740 out of 905 (81.8%) candidate Q1 lenses within its top 20 000 predictions, considering off-centred samples. Candidates span I E ≃ 17–24 AB mag (median 21.3 AB mag) and are redder in Y E − H E than the parent population, consistent with massive early-type deflectors. Each training iteration required about a week for a small team and the approach can easily be scaled to future wide-area Euclid releases. Subsequent works will focus on calibrating the selection function via lens injection, extending recall through uncertainty-aware active learning, and exploring multi-scale or attention-based neural networks with fast post hoc vetters that incorporate lens models into the classification.

Authors 100

1. X. Xu

   University of Southern California · University of California, Irvine

   Affiliation as printed

   Department of Physics & Astronomy, University of California Irvine

   University of Southern California

2. R. Chen

   University of California, Irvine

   Affiliation as printed

   Department of Physics & Astronomy, University of California Irvine

3. T. Li

   University of California, Irvine

   Affiliation as printed

   Department of Physics & Astronomy, University of California Irvine

4. Asantha Roshan Cooray

   University of California, Irvine

   Affiliation as printed

   Department of Physics & Astronomy, University of California Irvine

5. S. Schuldt

   University of Milan · National Institute for Astrophysics

   Affiliation as printed

   Dipartimento di Fisica “Aldo Pontremoli”, Università degli Studi di Milano

   INAF-IASF Milano

6. Javier A Acevedo Barroso

   Jet Propulsion Laboratory

   Affiliation as printed

   Jet Propulsion Laboratory, California Institute of Technology

7. Daniel K. Stern

   Jet Propulsion Laboratory

   Affiliation as printed

   Jet Propulsion Laboratory, California Institute of Technology

8. Douglas Scott

   University of British Columbia

   Affiliation as printed

   Department of Physics and Astronomy, University of British Columbia

9. Massimo Meneghetti

   Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

   Affiliation as printed

   INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

   INFN-Sezione di Bologna

10. Giulia Despali

    Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · University of Bologna

    Affiliation as printed

    Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

    INFN-Sezione di Bologna

11. J. Chopra

    University of California, Irvine

    Affiliation as printed

    Department of Physics & Astronomy, University of California Irvine

12. Cao Ye

    University of California, Irvine

    Affiliation as printed

    Department of Physics & Astronomy, University of California Irvine

13. M. Cheng

    University of California, Irvine

    Affiliation as printed

    Department of Physics & Astronomy, University of California Irvine

14. J. Buda

    University of California, Irvine

    Affiliation as printed

    Department of Physics & Astronomy, University of California Irvine

15. J. Zhang

    University of California, Irvine

    Affiliation as printed

    Department of Physics & Astronomy, University of California Irvine

16. J. Furumizo

    University of California, Irvine

    Affiliation as printed

    Department of Physics & Astronomy, University of California Irvine

17. R. Valencia

    University of California, Irvine

    Affiliation as printed

    Department of Physics & Astronomy, University of California Irvine

18. Z. Jiang

    University of Southern California

    Affiliation as printed

    University of Southern California

19. C. Tortora

    Astronomical Observatory of Capodimonte · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Capodimonte

20. N.E.P. Lines

    University of Portsmouth

    Affiliation as printed

    Institute of Cosmology and Gravitation, University of Portsmouth

21. Thomas E. Collett

    University of Portsmouth

    Affiliation as printed

    Institute of Cosmology and Gravitation, University of Portsmouth

22. S. Fotopoulou

    University of Bristol

    Affiliation as printed

    School of Physics, HH Wills Physics Laboratory, University of Bristol

23. Aymeric Galan

    Max Planck Institute for Astrophysics · Technical University of Munich

    Affiliation as printed

    Max-Planck-Institut für Astrophysik

    Technical University of Munich, TUM School of Natural Sciences, Physics Department

24. A. Manjón-García

    Universidad Politécnica de Cartagena

    Affiliation as printed

    Departamento Física Aplicada, Universidad Politécnica de Cartagena

25. R. Gavazzi

    Centre National de la Recherche Scientifique · Aix-Marseille Université · Institut d'Astrophysique de Paris · Sorbonne Université

    Affiliation as printed

    Aix-Marseille Université, CNRS, CNES, LAM

    Institut d’Astrophysique de Paris, UMR 7095, CNRS, and Sorbonne Université

26. Leena Iwamoto

    Center for Astrophysics Harvard & Smithsonian

    Affiliation as printed

    Center for Astrophysics | Harvard & Smithsonian

27. Sandor Kruk

    European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

28. Martin Millon

    University of Geneva

    Affiliation as printed

    Université de Genève, Département de Physique Théorique and Centre for Astroparticle Physics

29. P. Nugent

    Lawrence Berkeley National Laboratory

    Affiliation as printed

    Lawrence Berkeley National Laboratory

30. Christoph Saulder

    Max Planck Institute for Extraterrestrial Physics · Ludwig-Maximilians-Universität München

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

    Universitäts-Sternwarte München, Fakultät für Physik, Ludwig-Maximilians-Universität München

31. Dominique Sluse

    University of Liège

    Affiliation as printed

    STAR Institute, University of Liège, Quartier Agora

32. Joshua Wilde

    Institut de Ciències del Cosmos · Universitat de Barcelona

    Affiliation as printed

    Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB)

33. Mike Walmsley

    University of Toronto · University of Manchester

    Affiliation as printed

    David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto

    Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester

34. F. Courbin

    Institució Catalana de Recerca i Estudis Avançats · Institute of Space Sciences · Consejo Superior de Investigaciones Científicas · Institut de Ciències del Cosmos · Universitat de Barcelona

    Affiliation as printed

    Institució Catalana de Recerca i Estudis Avançats (ICREA)

    Institut de Ciencies de l’Espai (IEEC-CSIC)

    Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona (IEEC-UB)

35. R. B. Metcalf

    Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · University of Bologna

    Affiliation as printed

    Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

36. B. Altieri

    European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

37. A Amara

    University of Surrey

    Affiliation as printed

    School of Mathematics and Physics, University of Surrey

38. Stefano Andreon

    Brera Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Brera

39. N. Auricchio

    Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

40. C. Baccigalupi

    Scuola Internazionale Superiore di Studi Avanzati · Trieste Astronomical Observatory · Istituto Nazionale di Fisica Nucleare, Sezione di Trieste · Institute for Fundamental Physics of the Universe · National Institute for Astrophysics

    Affiliation as printed

    IFPU, Institute for Fundamental Physics of the Universe

    INAF-Osservatorio Astronomico di Trieste

    INFN, Sezione di Trieste

    SISSA, International School for Advanced Studies

41. Marco Baldi

    Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics · University of Bologna

    Affiliation as printed

    Dipartimento di Fisica e Astronomia, Università di Bologna

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

    INFN-Sezione di Bologna

42. A. Balestra

    Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Padova

43. S. Bardelli

    Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

44. Paola Maria Battaglia

    Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

45. Ralf Bender

    Max Planck Institute for Extraterrestrial Physics · Ludwig-Maximilians-Universität München

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

    Universitäts-Sternwarte München, Fakultät für Physik, Ludwig-Maximilians-Universität München

46. A. Biviano

    Trieste Astronomical Observatory · Institute for Fundamental Physics of the Universe · National Institute for Astrophysics

    Affiliation as printed

    IFPU, Institute for Fundamental Physics of the Universe

    INAF-Osservatorio Astronomico di Trieste

47. E. Branchini

    Brera Astronomical Observatory · Istituto Nazionale di Fisica Nucleare, Sezione di Genova · University of Genoa · National Institute for Astrophysics

    Affiliation as printed

    Dipartimento di Fisica, Università di Genova

    INAF-Osservatorio Astronomico di Brera

    INFN-Sezione di Genova

48. M. Brescia

    Astronomical Observatory of Capodimonte · University of Naples Federico II · National Institute for Astrophysics

    Affiliation as printed

    Department of Physics “E. Pancini”, University Federico II

    INAF-Osservatorio Astronomico di Capodimonte

49. S. Camera

    Istituto Nazionale di Fisica Nucleare, Sezione di Torino · Osservatorio Astrofisico di Torino · University of Turin · National Institute for Astrophysics

    Affiliation as printed

    Dipartimento di Fisica, Università degli Studi di Torino

    INAF-Osservatorio Astrofisico di Torino

    INFN-Sezione di Torino

50. V. Capobianco

    Osservatorio Astrofisico di Torino · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astrofisico di Torino

51. C. Carbone

    National Institute for Astrophysics

    Affiliation as printed

    INAF-IASF Milano

52. V. F. Cardone

    Astronomical Observatory of Rome · Istituto Nazionale di Fisica Nucleare, Sezione di Roma I · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Roma

    INFN-Sezione di Roma

53. J. Carretero

    Port d'Informació Científica · Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas

    Affiliation as printed

    Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT)

    Port d’Informació Científica

54. Santiago Casas Aachen Institute for Theoretical Particle Physics and Cosmology

    Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR) · RWTH Aachen University

    Affiliation as printed

    Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)

    Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University

55. M. Castellano

    Astronomical Observatory of Rome · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Roma

56. G. Castignani

    Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

57. S. Cavuoti

    Istituto Nazionale di Fisica Nucleare · Astronomical Observatory of Capodimonte · Istituto Nazionale di Fisica Nucleare, Sezione di Napoli · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Capodimonte

    INFN section of Naples

58. A. Cimatti

    University of Bologna

    Affiliation as printed

    Dipartimento di Fisica e Astronomia “Augusto Righi” – Alma Mater Studiorum Università di Bologna

59. C Colodro-Conde

    Instituto de Astrofísica de Canarias

    Affiliation as printed

    Instituto de Astrofísica de Canarias

60. G. Congedo

    Royal Observatory · University of Edinburgh

    Affiliation as printed

    Institute for Astronomy, University of Edinburgh, Royal Observatory

61. Christopher J. Conselice

    University of Manchester

    Affiliation as printed

    Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, University of Manchester

62. L. Conversi

    European Space Agency · European Space Astronomy Centre · European Space Research Institute

    Affiliation as printed

    ESAC/ESA

    European Space Agency/ESRIN

63. Y. Copin

    Lyon 1 Université · Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Institut de Physique des 2 Infinis de Lyon

    Affiliation as printed

    Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822

64. Hélène M. Courtois

    Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Institut de Physique des 2 Infinis de Lyon

    Affiliation as printed

    UCB Lyon 1, CNRS/IN2P3, IUF, IP2I Lyon

65. Mark S. Cropper

    University College London

    Affiliation as printed

    Mullard Space Science Laboratory, University College London

66. A. Da Silva

    University of Lisbon · Institute of Astrophysics and Space Sciences

    Affiliation as printed

    Departamento de Física, Faculdade de Ciências, Universidade de Lisboa

    Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências, Universidade de Lisboa

67. Hubert Degaudenzi

    University of Geneva

    Affiliation as printed

    Department of Astronomy, University of Geneva

68. G. De Lucia

    Trieste Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Trieste

69. C. Dolding

    University College London

    Affiliation as printed

    Mullard Space Science Laboratory, University College London

70. Herve A. Dole

    Centre National de la Recherche Scientifique · Université Paris-Saclay · Institut d'Astrophysique Spatiale

    Affiliation as printed

    Université Paris-Saclay, CNRS, Institut d’astrophysique spatiale

71. F. Dubath

    University of Geneva

    Affiliation as printed

    Department of Astronomy, University of Geneva

72. X. Dupac

    European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

73. S. Dusini

    Istituto Nazionale di Fisica Nucleare · Istituto Nazionale di Fisica Nucleare, Sezione di Padova

    Affiliation as printed

    INFN-Padova

74. S. Escoffier

    Centre National de la Recherche Scientifique · Aix-Marseille Université · Centre de physique des particules de Marseille · Institut National de Physique Nucléaire et de Physique des Particules

    Affiliation as printed

    Aix-Marseille Université, CNRS/IN2P3, CPPM

75. Maria Farina

    Institute for Space Astrophysics and Planetology · National Institute for Astrophysics

    Affiliation as printed

    INAF-Istituto di Astrofisica e Planetologia Spaziali

76. R Farinelli

    Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

77. S. Farrens

    Centre National de la Recherche Scientifique · Université Paris Cité · Commissariat à l'Énergie Atomique et aux Énergies Alternatives · Université Paris-Saclay · Astrophysique, Instrumentation et Modélisation

    Affiliation as printed

    Université Paris-Saclay, Université Paris Cité, CEA, CNRS, AIM

78. S Ferriol

    Lyon 1 Université · Centre National de la Recherche Scientifique · Institut National de Physique Nucléaire et de Physique des Particules · Institut de Physique des 2 Infinis de Lyon

    Affiliation as printed

    Université Claude Bernard Lyon 1, CNRS/IN2P3, IP2I Lyon, UMR 5822

79. Fabio Finelli

    Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

    INFN-Bologna

80. P. Fosalba

    Institute of Space Sciences · Institut d'Estudis Espacials de Catalunya · Universitat Politècnica de Catalunya

    Affiliation as printed

    Institut d’Estudis Espacials de Catalunya (IEEC), Edifici RDIT, Campus UPC

    Institute of Space Sciences (ICE, CSIC), Campus UAB

81. M. Frailis

    Trieste Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Trieste

82. Enrico Franceschi

    Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

83. M. Fumana

    National Institute for Astrophysics

    Affiliation as printed

    INAF-IASF Milano

84. Samuele Galeotta

    Trieste Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Trieste

85. Koshy George

    Ludwig-Maximilians-Universität München

    Affiliation as printed

    University Observatory, LMU Faculty of Physics

86. William Gillard

    Centre National de la Recherche Scientifique · Aix-Marseille Université · Centre de physique des particules de Marseille · Institut National de Physique Nucléaire et de Physique des Particules

    Affiliation as printed

    Aix-Marseille Université, CNRS/IN2P3, CPPM

87. Bryan R. Gillis

    Royal Observatory · University of Edinburgh

    Affiliation as printed

    Institute for Astronomy, University of Edinburgh, Royal Observatory

88. C. Giocoli

    Istituto Nazionale di Fisica Nucleare, Sezione di Bologna · Osservatorio di Astrofisica e Scienza dello Spazio · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

    INFN-Sezione di Bologna

89. P. Gómez-Álvarez

    European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

    FRACTAL S.L.N.E

90. Javier Graciá-Carpio

    Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

91. A. Grazian

    Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Padova

92. F Grupp

    Max Planck Institute for Extraterrestrial Physics · Ludwig-Maximilians-Universität München

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

    Universitäts-Sternwarte München, Fakultät für Physik, Ludwig-Maximilians-Universität München

93. S. V. H. Haugan

    University of Oslo

    Affiliation as printed

    Institute of Theoretical Astrophysics, University of Oslo

94. W. Holmes

    Jet Propulsion Laboratory

    Affiliation as printed

    Jet Propulsion Laboratory, California Institute of Technology

95. F. Hormuth
    Affiliation as printed

    Felix Hormuth Engineering

96. Allan Hornstrup

    Technical University of Denmark

    Affiliation as printed

    Cosmic Dawn Center (DAWN)

    Technical University of Denmark

97. K. Jahnkę

    Max Planck Institute for Astronomy

    Affiliation as printed

    Max-Planck-Institut für Astronomie

98. M. Jhabvala

    Goddard Space Flight Center

    Affiliation as printed

    NASA Goddard Space Flight Center

99. Benjamin Joachimi

    University College London

    Affiliation as printed

    Department of Physics and Astronomy, University College London

100. Smaïn Kermiche

     Centre National de la Recherche Scientifique · Aix-Marseille Université · Centre de physique des particules de Marseille · Institut National de Physique Nucléaire et de Physique des Particules

     Affiliation as printed

     Aix-Marseille Université, CNRS/IN2P3, CPPM