_version_ 1866915482916880384
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
de Graaff, Anna
Hirschmann, Michaela
Hviding, Raphael E.
Kokorev, Vasily
Leja, Joel
Liu, Hanpu
Ma, Yilun
Matthee, Jorryt
Nanayakkara, Themiya
Oesch, Pascal A.
Pan, Richard
Price, Sedona H.
Spilker, Justin S.
Wang, Bingjie
Weaver, John R.
Whitaker, Katherine E.
Williams, Christina C.
Zitrin, Adi
author_facet 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
de Graaff, Anna
Hirschmann, Michaela
Hviding, Raphael E.
Kokorev, Vasily
Leja, Joel
Liu, Hanpu
Ma, Yilun
Matthee, Jorryt
Nanayakkara, Themiya
Oesch, Pascal A.
Pan, Richard
Price, Sedona H.
Spilker, Justin S.
Wang, Bingjie
Weaver, John R.
Whitaker, Katherine E.
Williams, Christina C.
Zitrin, Adi
contents 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 their bolometric luminosities. We find evidence that more than half of the bolometric luminosity likely emerges in the rest-frame optical, with $L_{\rm bol}/L_{5100} = 5$, roughly half the value for ``standard'' Active Galactic Nuclei. Meanwhile, the X-ray emitting corona, UV-emitting black-body, and reprocessed mid to far-infrared emission are all considerably sub-dominant, 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 ten 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 {\bf (e.g., $\sim 10^5-10^7~{\rm M_{\odot}}$ black holes, and $\sim 10^8~{\rm M_{\odot}}$ galaxies)}, alleviating tensions with clustering, overmassive black holes, and the integrated black hole mass density in the Universe.
format Preprint
id arxiv_https___arxiv_org_abs_2509_05434
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle What you see is what you get: empirically measured bolometric luminosities of Little Red Dots
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
de Graaff, Anna
Hirschmann, Michaela
Hviding, Raphael E.
Kokorev, Vasily
Leja, Joel
Liu, Hanpu
Ma, Yilun
Matthee, Jorryt
Nanayakkara, Themiya
Oesch, Pascal A.
Pan, Richard
Price, Sedona H.
Spilker, Justin S.
Wang, Bingjie
Weaver, John R.
Whitaker, Katherine E.
Williams, Christina C.
Zitrin, Adi
Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
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 their bolometric luminosities. We find evidence that more than half of the bolometric luminosity likely emerges in the rest-frame optical, with $L_{\rm bol}/L_{5100} = 5$, roughly half the value for ``standard'' Active Galactic Nuclei. Meanwhile, the X-ray emitting corona, UV-emitting black-body, and reprocessed mid to far-infrared emission are all considerably sub-dominant, 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 ten 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 {\bf (e.g., $\sim 10^5-10^7~{\rm M_{\odot}}$ black holes, and $\sim 10^8~{\rm M_{\odot}}$ galaxies)}, alleviating tensions with clustering, overmassive black holes, and the integrated black hole mass density in the Universe.
title What you see is what you get: empirically measured bolometric luminosities of Little Red Dots
topic Astrophysics of Galaxies
Cosmology and Nongalactic Astrophysics
url https://arxiv.org/abs/2509.05434