The Astrophysical Journal Letters (Jan 2023)

A CEERS Discovery of an Accreting Supermassive Black Hole 570 Myr after the Big Bang: Identifying a Progenitor of Massive z > 6 Quasars

  • Rebecca L. Larson,
  • Steven L. Finkelstein,
  • Dale D. Kocevski,
  • Taylor A. Hutchison,
  • Jonathan R. Trump,
  • Pablo Arrabal Haro,
  • Volker Bromm,
  • Nikko J. Cleri,
  • Mark Dickinson,
  • Seiji Fujimoto,
  • Jeyhan S. Kartaltepe,
  • Anton M. Koekemoer,
  • Casey Papovich,
  • Nor Pirzkal,
  • Sandro Tacchella,
  • Jorge A. Zavala,
  • Micaela Bagley,
  • Peter Behroozi,
  • Jaclyn B. Champagne,
  • Justin W. Cole,
  • Intae Jung,
  • Alexa M. Morales,
  • Guang Yang,
  • Haowen Zhang,
  • Adi Zitrin,
  • Ricardo O. Amorín,
  • Denis Burgarella,
  • Caitlin M. Casey,
  • Óscar A. Chávez Ortiz,
  • Isabella G. Cox,
  • Katherine Chworowsky,
  • Adriano Fontana,
  • Eric Gawiser,
  • Andrea Grazian,
  • Norman A. Grogin,
  • Santosh Harish,
  • Nimish P. Hathi,
  • Michaela Hirschmann,
  • Benne W. Holwerda,
  • Stéphanie Juneau,
  • Gene C. K. Leung,
  • Ray A. Lucas,
  • Elizabeth J. McGrath,
  • Pablo G. Pérez-González,
  • Jane R. Rigby,
  • Lise-Marie Seillé,
  • Raymond C. Simons,
  • Alexander de la Vega,
  • Benjamin J. Weiner,
  • Stephen M. Wilkins,
  • L. Y. Aaron Yung,
  • and The CEERS Team

DOI
https://doi.org/10.3847/2041-8213/ace619
Journal volume & issue
Vol. 953, no. 2
p. L29

Abstract

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We report the discovery of an accreting supermassive black hole at z = 8.679. This galaxy, denoted here as CEERS_1019, was previously discovered as a Ly α -break galaxy by Hubble with a Ly α redshift from Keck. As part of the Cosmic Evolution Early Release Science (CEERS) survey, we have observed this source with JWST/NIRSpec, MIRI, NIRCam, and NIRCam/WFSS and uncovered a plethora of emission lines. The H β line is best fit by a narrow plus a broad component, where the latter is measured at 2.5 σ with an FWHM ∼1200 km s ^−1 . We conclude this originates in the broadline region of an active galactic nucleus (AGN). This is supported by the presence of weak high-ionization lines (N V, N IV], and C III]), as well as a spatial point-source component. The implied mass of the black hole (BH) is log ( M _BH / M _⊙ ) = 6.95 ± 0.37, and we estimate that it is accreting at 1.2 ± 0.5 times the Eddington limit. The 1–8 μ m photometric spectral energy distribution shows a continuum dominated by starlight and constrains the host galaxy to be massive (log M/M _⊙ ∼9.5) and highly star-forming (star formation rate, or SFR ∼ 30 M _⊙ yr ^−1 ; log sSFR ∼ − 7.9 yr ^−1 ). The line ratios show that the gas is metal-poor ( Z / Z _⊙ ∼ 0.1), dense ( n _e ∼ 10 ^3 cm ^−3 ), and highly ionized (log U ∼ − 2.1). We use this present highest-redshift AGN discovery to place constraints on BH seeding models and find that a combination of either super-Eddington accretion from stellar seeds or Eddington accretion from very massive BH seeds is required to form this object.

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