A CEERS Discovery of an Accreting Supermassive Black Hole 570 Myr after the Big Bang: Identifying a Progenitor of Massive z &gt; 6 Quasars
Creators: name: Larson, Rebecca L.
name: Finkelstein, Steven L.
name: Kocevski, Dale D.
name: Hutchison, Taylor A.
name: Trump, Jonathan R.
name: Haro, Pablo Arrabal
name: Bromm, Volker
name: Cleri, Nikko J.
name: Dickinson, Mark
name: Fujimoto, Seiji
name: Kartaltepe, Jeyhan S.
name: Koekemoer, Anton M.
name: Papovich, Casey
name: Pirzkal, Nor
name: Tacchella, Sandro
name: Zavala, Jorge A.
name: Bagley, Micaela
name: Behroozi, Peter
name: Champagne, Jaclyn B.
name: Cole, Justin W.
name: Jung, Intae
name: Morales, Alexa M.
name: Yang, Guang
name: Zhang, Haowen
name: Zitrin, Adi
name: Amorín, Ricardo O.
name: Burgarella, Denis
name: Casey, Caitlin M.
name: Ortiz, Óscar A. Chávez
name: Cox, Isabella G.
name: Chworowsky, Katherine
name: Fontana, Adriano
name: Gawiser, Eric
name: Grazian, Andrea
name: Grogin, Norman A.
name: Harish, Santosh
name: Hathi, Nimish P.
name: Hirschmann, Michaela
name: Holwerda, Benne W.
name: Juneau, Stéphanie
name: Leung, Gene C. K.
name: Lucas, Ray A.
name: McGrath, Elizabeth J.
name: Pérez-González, Pablo G.
name: Rigby, Jane R.
name: Seillé, Lise-Marie
name: Simons, Raymond C.
name: de la Vega, Alexander
name: Weiner, Benjamin J.
name: Wilkins, Stephen M.
name: Yung, L. Y. Aaron
name: Team, The CEERS
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the discovery of an accreting supermassive black hole at z=8.679, in CEERS_1019, a galaxy previously discovered via a Ly$α$-break by Hubble and with a Ly$α$ redshift from Keck. As part of the Cosmic Evolution Early Release Science (CEERS) survey, we observed this source with JWST/NIRSpec spectroscopy, MIRI and NIRCam imaging, and NIRCam/WFSS slitless spectroscopy. The NIRSpec spectra uncover many emission lines, and the strong [O III] emission line confirms the ground-based Ly$α$ redshift. We detect a significant broad (FWHM~1200 km/s) component in the H$β$ emission line, which we conclude originates in the broad-line region of an active galactic nucleus (AGN), as the lack of a broad component in the forbidden lines rejects an outflow origin. This hypothesis is supported by the presence of high-ionization lines, as well as a spatial point-source component embedded within a smoother surface brightness profile. The mass of the black hole is log($M_{BH}/M_{\odot})=6.95{\pm}0.37$, and we estimate that it is accreting at 1.2 ($\pm$0.5) x the Eddington limit. The 1-8 $μ$m photometric spectral energy distribution (SED) from NIRCam and MIRI shows a continuum dominated by starlight and constrains the host galaxy to be massive (log M/M$_{\odot}$~9.5) and highly star-forming (SFR~30 M$_{\odot}$ yr$^{-1}$). Ratios of the strong emission lines show that the gas in this galaxy is metal-poor (Z/Z$_{\odot}$~0.1), dense (n$_{e}$~10$^{3}$ cm$^{-3}$), and highly ionized (log U~-2.1), consistent with the general galaxy population observed with JWST at high redshifts. We use this presently highest-redshift AGN discovery to place constraints on black hole seeding models and find that a combination of either super-Eddington accretion from stellar seeds or Eddington accretion from massive black hole seeds is required to form this object by the observed epoch.
description: 26 pages, 14 figures, 6 tables, published in ApJL