A

Euclid Quick Data Release (Q1)

Astronomy and Astrophysics, vol. 711, pp. A21

Abstract

Light emission from galaxies exhibit diverse brightness profiles, influenced by factors such as galaxy type, structural features, and interactions with other galaxies. Elliptical galaxies feature more uniform light distributions, while spiral and irregular galaxies have complex, varied light profiles due to their structural heterogeneity and star-forming activity. In addition, galaxies with active galactic nuclei (AGN) feature intense, concentrated emission from gas accretion around supermassive black holes, superimposed on regular galactic light, while quasi-stellar objects (QSOs) represent extreme cases in which AGN emissions dominate their host galaxies. The challenge of identifying AGN and QSOs has been discussed many times in the literature, often requiring multi-wavelength observations. This paper introduces a novel approach to identify AGN and QSOs from a single image. Diffusion models have recently been developed in the machine-learning literature to generate realistic-looking images of everyday objects. Utilising the spatial resolving power of the Euclid VIS images, we created a diffusion model trained on one million sources, without using any source pre-selection or labels. The model learns to reconstruct light distributions of normal galaxies, since the population is dominated by them. We conditioned the prediction of the central light distribution by masking the central few pixels of each source and reconstructed the light according to the diffusion model. We further used this prediction to identify sources that deviate from this profile by examining the reconstruction error of the few central pixels regenerated in each source’s core. Our approach, solely using VIS imaging, features high completeness compared to traditional methods of AGN and QSO selection, including optical, near-infrared, mid-infrared, and X-rays. Our study offers practical insights for refining diffusion models and broadening their applications throughout the Euclid survey area, underscoring the utility of this approach in diverse astronomical contexts beyond just AGN identification.

Authors 88

  1. University of Bristol

    Affiliation as printed

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

  2. University of Bristol

    Affiliation as printed

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

  3. University of Bristol

    Affiliation as printed

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

  4. Max Planck Institute for Astronomy

    Affiliation as printed

    Max-Planck-Institut für Astronomie

  5. Space Research Organisation Netherlands

    Affiliation as printed

    SRON Netherlands Institute for Space Research

  6. University of Hertfordshire

    Affiliation as printed

    Aspia Space

    School of Physics, Astronomy and Mathematics, University of Hertfordshire

  7. 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

  8. Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

  9. 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

  10. Universidade do Porto · Institute of Astrophysics and Space Sciences · Centro de Astrofísica da Universidade do Porto

    Affiliation as printed

    Centro de Astrofísica da Universidade do Porto

    Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP

  11. Institute of Space Sciences · Universidad de La Laguna · Instituto de Astrofísica de Canarias

    Affiliation as printed

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

    Instituto de Astrofísica de Canarias (IAC); Departamento de Astrofísica, Universidad de La Laguna (ULL)

  12. 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

  13. Roma Tre University · Astronomical Observatory of Rome · National Institute for Astrophysics

    Affiliation as printed

    Department of Mathematics and Physics, Roma Tre University

    INAF-Osservatorio Astronomico di Roma

  14. Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

  15. 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

  16. 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

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

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

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

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

  19. 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

  20. 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

  21. 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

  22. 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

  23. Leiden University · European Space Agency · Leiden Observatory · European Space Research and Technology Centre

    Affiliation as printed

    European Space Agency/ESTEC

    Institute Lorentz, Leiden University

    Leiden Observatory, Leiden University

  24. Osservatorio Astrofisico di Torino · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astrofisico di Torino

  25. National Institute for Astrophysics

    Affiliation as printed

    INAF-IASF Milano

  26. Universitat Autònoma de Barcelona · 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, Campus UAB

  27. Astronomical Observatory of Rome · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Roma

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

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

  29. 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

  30. University of Hawaiʻi at Mānoa · University of Hawaii System

    Affiliation as printed

    Institute for Astronomy, University of Hawaii

  31. University of Bologna

    Affiliation as printed

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

  32. Instituto de Astrofísica de Canarias

    Affiliation as printed

    Instituto de Astrofísica de Canarias

  33. Royal Observatory · University of Edinburgh

    Affiliation as printed

    Institute for Astronomy, University of Edinburgh, Royal Observatory

  34. University of Manchester

    Affiliation as printed

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

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

    Affiliation as printed

    ESAC/ESA

    European Space Agency/ESRIN

  36. Centre National de la Recherche Scientifique · Aix-Marseille Université

    Affiliation as printed

    Aix-Marseille Université, CNRS, CNES, LAM

  37. Institució Catalana de Recerca i Estudis Avançats · Institut de Ciències del Cosmos · Universitat de Barcelona

    Affiliation as printed

    Institució Catalana de Recerca i Estudis Avançats (ICREA)

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

  38. 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

  39. University College London

    Affiliation as printed

    Mullard Space Science Laboratory, University College London

  40. 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

  41. University of Geneva

    Affiliation as printed

    Department of Astronomy, University of Geneva

  42. Trieste Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Trieste

  43. University of Geneva

    Affiliation as printed

    Department of Astronomy, University of Geneva

  44. European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

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

    Affiliation as printed

    INFN-Padova

  46. 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

  47. Institute for Space Astrophysics and Planetology · National Institute for Astrophysics

    Affiliation as printed

    INAF-Istituto di Astrofisica e Planetologia Spaziali

  48. 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

  49. Ludwig-Maximilians-Universität München

    Affiliation as printed

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

  50. 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

  51. Brera Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Brera

  52. Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Padova

  53. 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

  54. University of Oslo

    Affiliation as printed

    Institute of Theoretical Astrophysics, University of Oslo

  55. Lancaster University

    Affiliation as printed

    Department of Physics, Lancaster University

  56. Affiliation as printed

    Felix Hormuth Engineering

  57. Technical University of Denmark

    Affiliation as printed

    Cosmic Dawn Center (DAWN)

    Technical University of Denmark

  58. Centre National de la Recherche Scientifique · Institut d'Astrophysique de Paris · Sorbonne Université

    Affiliation as printed

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

  59. Goddard Space Flight Center

    Affiliation as printed

    NASA Goddard Space Flight Center

  60. Helsinki Institute of Physics

    Affiliation as printed

    Department of Physics and Helsinki Institute of Physics

  61. 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

  62. Jet Propulsion Laboratory

    Affiliation as printed

    Jet Propulsion Laboratory, California Institute of Technology

  63. 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

  64. 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

  65. Ludwig-Maximilians-Universität München

    Affiliation as printed

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

  66. University of Helsinki · Helsinki Institute of Physics

    Affiliation as printed

    Department of Physics

    Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki

  67. Centre National de la Recherche Scientifique · Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules

    Affiliation as printed

    Centre de Calcul de l’IN2P3/CNRS

  68. Centre National de la Recherche Scientifique · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Laboratoire d'Étude de l'Univers et des Phénomènes Extrêmes

    Affiliation as printed

    Laboratoire d’etude de l’Univers et des phenomenes eXtremes, Observatoire de Paris, Université PSL, Sorbonne Université, CNRS

  69. Centre National de la Recherche Scientifique · Aix-Marseille Université

    Affiliation as printed

    Aix-Marseille Université, CNRS, CNES, LAM

  70. University of Oslo

    Affiliation as printed

    Institute of Theoretical Astrophysics, University of Oslo

  71. University of Helsinki · Helsinki Institute of Physics

    Affiliation as printed

    Department of Physics

    Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki

  72. SKA Observatory

    Affiliation as printed

    SKA Observatory, Jodrell Bank, Lower Withington

  73. Centre National de la Recherche Scientifique · Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules

    Affiliation as printed

    Centre de Calcul de l’IN2P3/CNRS

  74. University of Milan · Istituto Nazionale di Fisica Nucleare, Sezione di Milano · National Institute for Astrophysics

    Affiliation as printed

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

    INAF-IASF Milano

    INFN-Sezione di Milano

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

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

  76. University of Bonn

    Affiliation as printed

    Universität Bonn, Argelander-Institut für Astronomie

  77. 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

  78. Centre National de la Recherche Scientifique · Aix-Marseille Université

    Affiliation as printed

    Aix-Marseille Université, CNRS, CNES, LAM

  79. 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

  80. Durham University

    Affiliation as printed

    Department of Physics, Institute for Computational Cosmology, Durham University

  81. Centre National de la Recherche Scientifique · Université Côte d'Azur · Lagrange Laboratory · Observatoire de la Côte d’Azur

    Affiliation as printed

    Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange

  82. Centre National de la Recherche Scientifique · Institut d'Astrophysique de Paris · Sorbonne Université

    Affiliation as printed

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

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

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

  84. Centre National de la Recherche Scientifique · Université Paris Cité · Centre Pierre Binétruy · University of California, Berkeley

    Affiliation as printed

    CNRS-UCB International Research Laboratory, Centre Pierre Binetruy, IRL2007

    Université Paris Cité, CNRS, Astroparticule et Cosmologie

  85. FHNW University of Applied Sciences and Arts Northwestern Switzerland

    Affiliation as printed

    University of Applied Sciences and Arts of Northwestern Switzerland, School of Engineering

  86. 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

  87. Astronomical Observatory of Rome · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Roma

  88. École Polytechnique Fédérale de Lausanne

    Affiliation as printed

    Institute of Physics, Laboratory of Astrophysics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny

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