---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
PlanS_conform: '1'
_id: '23042'
abstract:
- lang: eng
  text: One of the most surprising results of early James Webb Space Telescope (JWST)
    observations is the discovery of an abundance of red, compact, broad-line objects
    dubbed “little red dots” (LRDs) at z > 4. Their spatial density (∼10−4–10−5 cMpc−3)
    is 100 times more abundant than UV-selected quasars at that redshift if one extrapolates
    the quasar luminosity function (QLF) down to the LRD regime. However, whether
    LRDs dominate black hole accretion at quasar-like luminosities (Lbol ≳ 1045−46
    erg s−1) remains unanswered, as probing the bright end of the LRD luminosity function
    requires a much larger area than that which is able to be surveyed by JWST. In
    this work, we present our search for the brightest LRDs (K < 23.7) at 4.5 < z
    < 4.9 using wide-area multiwavelength imaging surveys from the near-UV to the
    infrared bands. With over 15 deg2 of sky coverage, we only identify one single
    LRD candidate at zphot ≈ 4.6, which translates into a spatial density of n(M5100
    < −23.5) ≈ 10−8 cMpc−3—this is nearly 10 times less abundant than the UV-selected
    quasars at similar optical luminosity. When combined with the LRD sample identified
    by JWST at the same redshift range, we find a sharp cutoff in the optical luminosity
    function at λL5100 ≈ 2.2 × 1044 erg s−1, while the quasar luminosity function
    (QLF) turnover occurs at ≳20 times higher luminosity. We therefore confirm the
    exclusively low-luminosity nature of LRDs, ruling out that LRDs are the counterparts
    of quasars. Furthermore, we speculate that, if the shape of the luminosity function
    holds up, it points to LRDs being powered by low-mass black holes with a narrow
    range of Eddington-level accretion rates.
acknowledgement: "Y.M. thanks Hanpu Liu and Minghao Guo for useful discussion. Y.M.
  is also grateful for the suggestions from Xiaowei Ou and Jiaxuan Li on figure improvement.
  M.A. acknowledges support by the National Aeronautics and Space Administration (NASA)
  through an award (RSA 1628138) issued by JPL/Caltech. D.M., L.R., and A.S. acknowledge
  support by NASA under award No. 80NSSC21K0630, issued through the Astrophysics Data
  Analysis Program (ADAP).\r\n\r\nThe Hyper Suprime-Cam (HSC) collaboration includes
  the astronomical communities of Japan, Taiwan, and Princeton University. The HSC
  instrumentation and software were developed by the National Astronomical Observatory
  of Japan (NAOJ), the Kavli Institute for the Physics and Mathematics of the Universe
  (Kavli IPMU), the University of Tokyo, the High Energy Accelerator Research Organization
  (KEK), the Academia Sinica Institute for Astronomy and Astrophysics in Taiwan (ASIAA),
  and Princeton University. Funding was contributed by the FIRST program from the
  Japanese Cabinet Office, the Ministry of Education, Culture, Sports, Science and
  Technology (MEXT), the Japan Society for the Promotion of Science (JSPS), Japan
  Science and Technology Agency (JST), the Toray Science Foundation, NAOJ, Kavli IPMU,
  KEK, ASIAA, and Princeton University.\r\n\r\nThis Letter is based in part on data
  collected at the Subaru Telescope and retrieved from the HSC data archive system,
  which is operated by Subaru Telescope and Astronomy Data Center (ADC) at NAOJ. Data
  analysis was in part carried out with the cooperation of Center for Computational
  Astrophysics (CfCA) at NAOJ. We are honored and grateful for the opportunity of
  observing the Universe from Maunakea, which has the cultural, historical, and natural
  significance in Hawai‘i.\r\n\r\nThis Letter makes use of software developed for
  Vera C. Rubin Observatory (M. Juric et al. 2017; J. Bosch et al. 2019; Ž. Ivezić
  et al. 2019). We thank the Rubin Observatory for making their code available as
  free software at http://pipelines.lsst.io/.\r\n\r\nThis Letter also partially makes
  use of the CLAUDS data (M. Sawicki et al. 2019), whose data products can be accessed
  from https://www.clauds.net."
article_number: L64
article_processing_charge: Yes
article_type: original
arxiv: 1
author:
- first_name: Yilun
  full_name: Ma, Yilun
  last_name: Ma
- first_name: Jenny E.
  full_name: Greene, Jenny E.
  last_name: Greene
- first_name: Marta
  full_name: Volonteri, Marta
  last_name: Volonteri
- first_name: Andy D.
  full_name: Goulding, Andy D.
  last_name: Goulding
- first_name: David J.
  full_name: Setton, David J.
  last_name: Setton
- first_name: Marianna
  full_name: Annunziatella, Marianna
  last_name: Annunziatella
- first_name: Eiichi
  full_name: Egami, Eiichi
  last_name: Egami
- first_name: Xiaohui
  full_name: Fan, Xiaohui
  last_name: Fan
- first_name: Vasily
  full_name: Kokorev, Vasily
  last_name: Kokorev
- first_name: Ivo
  full_name: Labbe, Ivo
  last_name: Labbe
- first_name: Xiaojing
  full_name: Lin, Xiaojing
  last_name: Lin
- first_name: Danilo
  full_name: Marchesini, Danilo
  last_name: Marchesini
- first_name: Jorryt J
  full_name: Matthee, Jorryt J
  id: 7439a258-f3c0-11ec-9501-9df22fe06720
  last_name: Matthee
  orcid: 0000-0003-2871-127X
- first_name: Themiya
  full_name: Nanayakkara, Themiya
  last_name: Nanayakkara
- first_name: Luke
  full_name: Robbins, Luke
  last_name: Robbins
- first_name: Anna
  full_name: Sajina, Anna
  last_name: Sajina
- first_name: Marcin
  full_name: Sawicki, Marcin
  last_name: Sawicki
citation:
  ama: 'Ma Y, Greene JE, Volonteri M, et al. No luminous Little Red Dots: A sharp
    cutoff in their luminosity function. <i>The Astrophysical Journal Letters</i>.
    2026;1008(2). doi:<a href="https://doi.org/10.3847/2041-8213/aea071">10.3847/2041-8213/aea071</a>'
  apa: 'Ma, Y., Greene, J. E., Volonteri, M., Goulding, A. D., Setton, D. J., Annunziatella,
    M., … Sawicki, M. (2026). No luminous Little Red Dots: A sharp cutoff in their
    luminosity function. <i>The Astrophysical Journal Letters</i>. IOP Publishing.
    <a href="https://doi.org/10.3847/2041-8213/aea071">https://doi.org/10.3847/2041-8213/aea071</a>'
  chicago: 'Ma, Yilun, Jenny E. Greene, Marta Volonteri, Andy D. Goulding, David J.
    Setton, Marianna Annunziatella, Eiichi Egami, et al. “No Luminous Little Red Dots:
    A Sharp Cutoff in Their Luminosity Function.” <i>The Astrophysical Journal Letters</i>.
    IOP Publishing, 2026. <a href="https://doi.org/10.3847/2041-8213/aea071">https://doi.org/10.3847/2041-8213/aea071</a>.'
  ieee: 'Y. Ma <i>et al.</i>, “No luminous Little Red Dots: A sharp cutoff in their
    luminosity function,” <i>The Astrophysical Journal Letters</i>, vol. 1008, no.
    2. IOP Publishing, 2026.'
  ista: 'Ma Y, Greene JE, Volonteri M, Goulding AD, Setton DJ, Annunziatella M, Egami
    E, Fan X, Kokorev V, Labbe I, Lin X, Marchesini D, Matthee JJ, Nanayakkara T,
    Robbins L, Sajina A, Sawicki M. 2026. No luminous Little Red Dots: A sharp cutoff
    in their luminosity function. The Astrophysical Journal Letters. 1008(2), L64.'
  mla: 'Ma, Yilun, et al. “No Luminous Little Red Dots: A Sharp Cutoff in Their Luminosity
    Function.” <i>The Astrophysical Journal Letters</i>, vol. 1008, no. 2, L64, IOP
    Publishing, 2026, doi:<a href="https://doi.org/10.3847/2041-8213/aea071">10.3847/2041-8213/aea071</a>.'
  short: Y. Ma, J.E. Greene, M. Volonteri, A.D. Goulding, D.J. Setton, M. Annunziatella,
    E. Egami, X. Fan, V. Kokorev, I. Labbe, X. Lin, D. Marchesini, J.J. Matthee, T.
    Nanayakkara, L. Robbins, A. Sajina, M. Sawicki, The Astrophysical Journal Letters
    1008 (2026).
das_tickbox: '0'
date_created: 2026-10-04T22:01:53Z
date_published: 2026-09-10T00:00:00Z
date_updated: 2026-10-07T10:33:29Z
day: '10'
ddc:
- '520'
department:
- _id: JoMa
doi: 10.3847/2041-8213/aea071
external_id:
  arxiv:
  - '2509.02662'
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fulldoi: https://doi.org/10.3847/2041-8213/aea071
has_accepted_license: '1'
intvolume: '      1008'
issue: '2'
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '09'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal Letters
publication_identifier:
  eissn:
  - 2041-8213
  issn:
  - 2041-8205
publication_status: published
publisher: IOP Publishing
quality_controlled: '1'
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status: public
supplementarymaterial: yes
title: 'No luminous Little Red Dots: A sharp cutoff in their luminosity function'
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