What you see is what you get: Empirically measured bolometric luminosities of Little Red Dots
Greene JE, Setton DJ, Furtak LJ, Naidu RP, Volonteri M, Dayal P, Labbe I, Van Dokkum P, Bezanson R, Brammer G, Cutler SE, Glazebrook K, De Graaff A, Hirschmann M, Hviding RE, Kokorev V, Leja J, Liu H, Ma Y, Matthee JJ, Nanayakkara T, Oesch PA, Pan R, Price SH, Spilker JS, Wang B, Weaver JR, Whitaker KE, Williams CC, Zitrin A. 2026. What you see is what you get: Empirically measured bolometric luminosities of Little Red Dots. The Astrophysical Journal. 996(2), 129.
Download
Journal Article
| Published
| English
Scopus indexed
Author
Greene, Jenny E.;
Setton, David J.;
Furtak, Lukas J.;
Naidu, Rohan P.;
Volonteri, Marta;
Dayal, Pratika;
Labbe, Ivo;
Van Dokkum, Pieter;
Bezanson, Rachel;
Brammer, Gabriel;
Cutler, Sam E.;
Glazebrook, Karl
All
All
Department
Abstract
New populations of red active galactic nuclei (known as “little red dots”) discovered by JWST exhibit remarkable spectral energy distributions. Leveraging X-ray through far-infrared observations of two of the most luminous known little red dots, we directly measure their bolometric luminosities. We find evidence that more than half of the bolometric luminosity likely emerges in the rest-frame optical, with Lbol/L5100 = 5, roughly half the value for “standard” active galactic nuclei. Meanwhile, the X-ray emitting corona, UV-emitting blackbody, and reprocessed mid to far-infrared emission are all considerably subdominant, assuming that the far-infrared luminosity is well below current measured limits. We present new bolometric corrections that dramatically lower inferred bolometric luminosities by a factor of 10 compared to published values in the literature. These bolometric corrections are in accord with expectations from models in which gas absorption and reprocessing are responsible for the red rest-frame optical colors of little red dots. We discuss how this lowered luminosity scale suggests a lower mass scale for the population by at least an order of magnitude (e.g., ∼105–107 M⊙ black holes, and ∼108 M⊙ galaxies), alleviating tensions with clustering, overmassive black holes, and the integrated black hole mass density in the Universe.
Publishing Year
Date Published
2026-01-10
Journal Title
The Astrophysical Journal
Publisher
IOP Publishing
Acknowledgement
We benefit from the following JWST programs: UNCOVER (JWST/GO #2561; Labbé & Bezanson); ALT (JWST-GO #3516; Naidu & Matthee); MegaScience (JWST-GO #4111; Suess); RUBIES (JWST-GO #4233; de Graaff & Brammer); PRIMER (JWST/GO #1837; Dunlop).
We acknowledge funding from NSF/AAG #2306950, JWST-GO-02561, JWST-GO-03516, and JWST-GO-04111, provided through a grant from the STScI under NASA contract NAS5-03127. I.L. acknowledges support from Australian Research Council Future Fellowship FT220100798. K.G. and T.N. acknowledge support from Australian Research Council Laureate Fellowship FL180100060. A.Z. acknowledges support by grant No. 2020750 from the United States-Israel Binational Science Foundation (BSF) and grant No. 2109066 from the United States National Science Foundation (NSF); by the Ministry of Science & Technology, Israel; and by the Israel Science Foundation grant No. 864/23. J.M. and I.K. are funded by the European Union (ERC, AGENTS, 101076224). Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. Y.F. acknowledges support from JSPS KAKENHI grant No. JSPS KAKENHI grant Nos. JP22K21349 and JP23K13149. This work has received funding from the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract No. MB22.00072, as well as from the Swiss National Science Foundation (SNSF) through project grant 200020_207349. The Cosmic Dawn Center (DAWN) is funded by the Danish National Research Foundation under grant DNRF140. Support for this work for RPN was provided by NASA through the NASA Hubble Fellowship grant HST-HF2-51515.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. The work of CCW is supported by NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation. J.M. acknowledges funding by the European Union (ERC, AGENTS, 101076224). R.E.H. acknowledges support by the German Aerospace Center (DLR) and the Federal Ministry for Economic Affairs and Energy (BMWi) through program 50OR2403 “RUBIES.”
Volume
996
Issue
2
Article Number
129
ISSN
eISSN
IST-REx-ID
Cite this
Greene JE, Setton DJ, Furtak LJ, et al. What you see is what you get: Empirically measured bolometric luminosities of Little Red Dots. The Astrophysical Journal. 2026;996(2). doi:10.3847/1538-4357/ae1836
Greene, J. E., Setton, D. J., Furtak, L. J., Naidu, R. P., Volonteri, M., Dayal, P., … Zitrin, A. (2026). What you see is what you get: Empirically measured bolometric luminosities of Little Red Dots. The Astrophysical Journal. IOP Publishing. https://doi.org/10.3847/1538-4357/ae1836
Greene, Jenny E., David J. Setton, Lukas J. Furtak, Rohan P. Naidu, Marta Volonteri, Pratika Dayal, Ivo Labbe, et al. “What You See Is What You Get: Empirically Measured Bolometric Luminosities of Little Red Dots.” The Astrophysical Journal. IOP Publishing, 2026. https://doi.org/10.3847/1538-4357/ae1836.
J. E. Greene et al., “What you see is what you get: Empirically measured bolometric luminosities of Little Red Dots,” The Astrophysical Journal, vol. 996, no. 2. IOP Publishing, 2026.
Greene JE, Setton DJ, Furtak LJ, Naidu RP, Volonteri M, Dayal P, Labbe I, Van Dokkum P, Bezanson R, Brammer G, Cutler SE, Glazebrook K, De Graaff A, Hirschmann M, Hviding RE, Kokorev V, Leja J, Liu H, Ma Y, Matthee JJ, Nanayakkara T, Oesch PA, Pan R, Price SH, Spilker JS, Wang B, Weaver JR, Whitaker KE, Williams CC, Zitrin A. 2026. What you see is what you get: Empirically measured bolometric luminosities of Little Red Dots. The Astrophysical Journal. 996(2), 129.
Greene, Jenny E., et al. “What You See Is What You Get: Empirically Measured Bolometric Luminosities of Little Red Dots.” The Astrophysical Journal, vol. 996, no. 2, 129, IOP Publishing, 2026, doi:10.3847/1538-4357/ae1836.
All files available under the following license(s):
Creative Commons Attribution 4.0 International Public License (CC-BY 4.0):
Main File(s)
File Name
2026_AstrophysicalJour_Greene.pdf
684.40 KB
Access Level
Open Access
Date Uploaded
2026-05-04
MD5 Checksum
7b3cb025d4bcaa35c6e52bd0c8fb6cf4
Export
Marked PublicationsOpen Data ISTA Research Explorer
Sources
arXiv 2509.05434
