{
  "abstract": "We tested whether the so-called little red dots (LRDs) are the dust-reddened high-inclination counterparts of bluer compact broad-line active galactic nuclei, here referred to as little blue dots (LBDs), by modeling their relative number densities and luminosities. Using the observed ultraviolet (UV) luminosity function (LF) of broad-line active galactic nuclei (BLAGNs) at z ≳ 4 as the parent distribution, we forward-modeled the effects of the accretion rate, anisotropic emission, orientation, and dust obscuration within our super-Eddington unification framework. We show that a model with a geometrically thick accretion flow and a dusty circumnuclear cloud population reproduces the LRD LF over the luminosity range currently constrained by the James Webb Space Telescope. The predicted LRD-to-BLAGN ratio is strongly luminosity dependent, rising from ≃3% at M ₁₅₀₀ = −21 mag to a peak value of ∼20% near M ₁₅₀₀ ≃ −19. The model also predicts a larger apparent LRD fraction at rest-frame optical wavelengths, reaching 27% at M ₄₅₀₀ = −20 mag and 39% at M ₆₅₀₀ = −21. The fiducial solution adopted a baseline host extinction A V host = 0.5 mag, a characteristic per-cloud nuclear extinction ⟨ A V c ⟩ = 3.0 mag, and a gray R V = 5.5 attenuation curve, and it yields a mean dust covering factor ⟨ C dust ⟩≃0.23. These results can support an orientation-based unification of little dots and identify the LRD LF as a key demographic test of rapid accretion onto infant black holes at cosmic dawn. In our model, the UV continuum is dominated by the active nucleus; LRDs and LBDs are drawn from the same observed BLAGN UV LF, but attenuation makes UV-selected LRDs intrinsically brighter and their inferred black holes more massive at fixed observed M ₁₅₀₀ .",
  "abstract_shown": true,
  "affiliations": [
    "Dipartimento di Fisica “G. Occhialini”, Università degli Studi di Milano-Bicocca",
    "Department of Astronomy & Astrophysics, University of California",
    "Kavli Institute for Cosmology, University of Cambridge",
    "Cavendish Laboratory, University of Cambridge",
    "Department of Physics and Astronomy, University College London"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Piero Madau",
      "orcid": "0000-0002-6336-3293"
    },
    {
      "affs": [
        2,
        3,
        4
      ],
      "name": "Roberto Maiolino",
      "orcid": "0000-0002-4985-3819"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6f34ygdz7bver.bib",
  "cited_by": 1,
  "doi": "10.1051/0004-6361/202660815",
  "fulltext_url": null,
  "id": "6f34ygdz7bver",
  "issns": [
    "0004-6361",
    "1432-0746"
  ],
  "landing_url": "https://www.aanda.org/10.1051/0004-6361/202660815",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7160548849",
  "pdf_url": null,
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-28",
  "publisher": "EDP Sciences",
  "ris": "https://research.draconitic.com/paper/6f34ygdz7bver.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:18Z",
      "native_id": "10.1051/0004-6361/202660815",
      "source": "crossref",
      "url": "https://www.aanda.org/10.1051/0004-6361/202660815"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "Little red dots as obscured little blue dots: Relative abundances, luminosities, and black hole masses",
  "title_text": "Little red dots as obscured little blue dots: Relative abundances, luminosities, and black hole masses",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:18Z",
  "url": "https://research.draconitic.com/paper/6f34ygdz7bver",
  "venue": "Astronomy & Astrophysics",
  "versions": []
}