Euclid Quick Data Release (Q1)

Astronomy and Astrophysics, vol. 711, pp. A24

Abstract

Recent observations with the James Webb Space Telescope (JWST) have revealed an interesting population of sources with a compact morphology and a characteristic v-shaped continuum, namely blue at a rest frame λ < 4000 Å and red at longer wavelengths. The nature of these sources, which are called little red dots (LRDs), is still highly debated because it is unclear whether they host active galactic nuclei (AGNs) and their number seems to drop drastically at z < 4. We took advantage of the 63 deg 2 covered by the Euclid Quick Data Release (Q1) to extend the search for LRDs to brighter magnitudes and lower redshifts than what was possible with JWST. This is fundamental for a broader view of the evolution of this peculiar galaxy population. The selection was performed by fitting the available photometric data ( Euclid , the Spitzer Infrared Array Camera (IRAC), and ground-based griz data) with two power laws to retrieve the rest-frame optical and UV slopes consistently over a wide redshift range (i.e. z < 7.6). We then excluded extended objects and possible line emitters and inspected the data visually to remove any imaging artefacts. The final selection included 3341 LRD candidates from z = 0.33 to z = 3.6, 29 of which were also detected in IRAC. The resulting rest-frame UV luminosity function, in contrast with previous JWST studies, shows that the number density of LRD candidates increases from high redshift to z = 1.5–2.5 and decreases at even lower redshifts. The subsample of more robust LRD candidates that are also detected with IRAC show a weaker evolution, however, which is affected by low statistics and limited by the IRAC resolution. The comparison with previous quasar UV luminosity functions shows that LRDs are not the dominant AGN population at z < 4 and M UV < −21. Follow-up studies of these LRD candidates are pivotal to confirm their nature, probe their physical properties, and determine whether they are compatible with JWST sources because the different spatial resolution and wavelength coverage of Euclid and JWST might select different samples of compact sources.

Authors 97

1. L Bisigello

   Osservatorio Astronomico di Padova · National Institute for Astrophysics

   Affiliation as printed

   INAF-Osservatorio Astronomico di Padova

2. Giulia Rodighiero

   University of Padua · Osservatorio Astronomico di Padova · National Institute for Astrophysics

   Affiliation as printed

   Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova

   INAF-Osservatorio Astronomico di Padova

3. S. Fotopoulou

   University of Bristol

   Affiliation as printed

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

4. Federica Ricci

   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

5. K. Jahnkę

   Max Planck Institute for Astronomy

   Affiliation as printed

   Max-Planck-Institut für Astronomie

6. A. Feltre

   Arcetri Astrophysical Observatory · National Institute for Astrophysics

   Affiliation as printed

   INAF-Osservatorio Astrofisico di Arcetri

7. V. Allevato

   Astronomical Observatory of Capodimonte · National Institute for Astrophysics

   Affiliation as printed

   INAF-Osservatorio Astronomico di Capodimonte

8. F. Shankar

   University of Southampton

   Affiliation as printed

   School of Physics & Astronomy, University of Southampton

9. P. Cassata

   University of Padua · Osservatorio Astronomico di Padova · National Institute for Astrophysics

   Affiliation as printed

   Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova

   INAF-Osservatorio Astronomico di Padova

10. E. Dalla Bontà

    University of Padua · University of Lancashire · Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova

    INAF-Osservatorio Astronomico di Padova

    Jeremiah Horrocks Institute, University of Central Lancashire

11. Marika Giulietti

    Istituto di Radioastronomia di Bologna · National Institute for Astrophysics

    Affiliation as printed

    INAF, Istituto di Radioastronomia

12. A. Grazian

    Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Padova

13. R. Maiolino

    University of Cambridge

    Affiliation as printed

    Cavendish Laboratory, University of Cambridge

14. T. Matamoro Zatarain

    University of Bristol

    Affiliation as printed

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

15. Mar Mezcua

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

    Affiliation as printed

    Institut d’Estudis Espacials de Catalunya (IEEC)

    Institute of Space Sciences (ICE, CSIC)

16. Isabella Prandoni

    Istituto di Radioastronomia di Bologna · National Institute for Astrophysics

    Affiliation as printed

    INAF, Istituto di Radioastronomia

17. D. Roberts

    University of Southampton

    Affiliation as printed

    School of Physics & Astronomy, University of Southampton

18. W. Roster

    Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

19. Mara Salvato

    Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

20. M. Siudek

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

    Affiliation as printed

    Institute of Space Sciences (ICE, CSIC)

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

21. F. Tarsitano

    University of Geneva

    Affiliation as printed

    Department of Astronomy, University of Geneva

22. Yoshiki Toba

    Institute of Astronomy and Astrophysics, Academia Sinica · Ritsumeikan University · National Astronomical Observatory of Japan · Academia Sinica

    Affiliation as printed

    Academia Sinica Institute of Astronomy and Astrophysics (ASIAA)

    Department of Physical Sciences, Ritsumeikan University

    National Astronomical Observatory of Japan

23. A. Vietri

    University of Padua

    Affiliation as printed

    Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova

24. Lingyu Wang Aachen SRON Netherlands Institute for Space Research

    University of Groningen · Space Research Organisation Netherlands

    Affiliation as printed

    Kapteyn Astronomical Institute, University of Groningen

    SRON Netherlands Institute for Space Research

25. G. Zamorani

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

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

26. M. Baes

    Ghent University

    Affiliation as printed

    Sterrenkundig Observatorium, Universiteit Gent

27. S. Belladitta

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

    Affiliation as printed

    INAF-Osservatorio di Astrofisica e Scienza dello Spazio di Bologna

    Max-Planck-Institut für Astronomie

28. Angelos Nersesian

    University of Liège · Ghent University

    Affiliation as printed

    STAR Institute, University of Liège

    Sterrenkundig Observatorium, Universiteit Gent

29. Luigi Spinoglio

    Institute for Space Astrophysics and Planetology · National Institute for Astrophysics

    Affiliation as printed

    INAF-Istituto di Astrofisica e Planetologia Spaziali

30. X. Lopez Lopez

    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

31. N. Aghanim

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

    Affiliation as printed

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

32. B. Altieri

    European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

33. Adam Amara

    University of Surrey

    Affiliation as printed

    School of Mathematics and Physics, University of Surrey

34. Stefano Andreon

    Brera Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Brera

35. 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

36. Hervé Aussel

    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

37. 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

38. 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

39. A. Balestra

    Osservatorio Astronomico di Padova · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Padova

40. 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

41. Alberto Basset

    Centre National d'Études Spatiales

    Affiliation as printed

    Centre National d’Etudes Spatiales – Centre spatial de Toulouse

42. 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

43. 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-Universitäts-München

44. 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

45. Andrea Bonchi

    Agenzia Spaziale Italiana

    Affiliation as printed

    Space Science Data Center, Italian Space Agency

46. 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

47. 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

48. J. Brinchmann

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

    Affiliation as printed

    Faculdade de Ciências da Universidade do Porto

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

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. G Cañas-Herrera Aachen Institute Lorentz Leiden Observatory

    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

51. V. Capobianco

    Osservatorio Astrofisico di Torino · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astrofisico di Torino

52. C. Carbone

    National Institute for Astrophysics

    Affiliation as printed

    INAF-IASF Milano

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

    RWTH Aachen University

    Affiliation as printed

    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. K. C. Chambers

    University of Hawaiʻi at Mānoa · University of Hawaii System

    Affiliation as printed

    Institute for Astronomy, University of Hawaii

59. A Cimatti

    University of Bologna

    Affiliation as printed

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

60. C Colodro-Conde

    Instituto de Astrofísica de Canarias

    Affiliation as printed

    Instituto de Astrofísica de Canarias

61. G. Congedo

    Royal Observatory · University of Edinburgh

    Affiliation as printed

    Institute for Astronomy, University of Edinburgh, Royal Observatory

62. Christopher J. Conselice

    University of Manchester

    Affiliation as printed

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

63. L. Conversi

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

    Affiliation as printed

    ESAC/ESA

    European Space Agency/ESRIN

64. 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

65. F Courbin

    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)

66. 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

67. Mark S. Cropper

    University College London

    Affiliation as printed

    Mullard Space Science Laboratory, University College London

68. 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

69. Hubert Degaudenzi

    University of Geneva

    Affiliation as printed

    Department of Astronomy, University of Geneva

70. G. De Lucia

    Trieste Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Trieste

71. Anna M. Di Giorgio

    Institute for Space Astrophysics and Planetology · National Institute for Astrophysics

    Affiliation as printed

    INAF-Istituto di Astrofisica e Planetologia Spaziali

72. C. Dolding

    University College London

    Affiliation as printed

    Mullard Space Science Laboratory, University College London

73. 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

74. F. Dubath

    University of Geneva

    Affiliation as printed

    Department of Astronomy, University of Geneva

75. C. A. J. Duncan

    University of Manchester

    Affiliation as printed

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

76. X. Dupac

    European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

77. S. Dusini

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

    Affiliation as printed

    INFN-Padova

78. A. Ealet

    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. 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

80. Maria Farina

    Institute for Space Astrophysics and Planetology · National Institute for Astrophysics

    Affiliation as printed

    INAF-Istituto di Astrofisica e Planetologia Spaziali

81. 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

82. F Faustini

    Astronomical Observatory of Rome · Agenzia Spaziale Italiana · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Roma

    Space Science Data Center, Italian Space Agency

83. 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

84. 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

85. M. Frailis

    Trieste Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Trieste

86. 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

87. Samuele Galeotta

    Trieste Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Trieste

88. Koshy George

    Ludwig-Maximilians-Universität München

    Affiliation as printed

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

89. 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

90. Gillis B

    Royal Observatory · University of Edinburgh

    Affiliation as printed

    Institute for Astronomy, University of Edinburgh, Royal Observatory

91. 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

92. P. Gómez-Álvarez

    European Space Agency · European Space Astronomy Centre

    Affiliation as printed

    ESAC/ESA

    FRACTAL S.L.N.E

93. Javier Graciá-Carpio

    Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics

94. B. R. Granett

    Brera Astronomical Observatory · National Institute for Astrophysics

    Affiliation as printed

    INAF-Osservatorio Astronomico di Brera

95. 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-Universitäts-München

96. Stephen Gwyn

    Herzberg Institute of Astrophysics · National Research Council Canada

    Affiliation as printed

    NRC Herzberg

97. S. V. H. Haugan

    University of Oslo

    Affiliation as printed

    Institute of Theoretical Astrophysics, University of Oslo