학술논문
A CEERS Discovery of an Accreting Supermassive Black Hole 570 Myr after the Big Bang: Identifying a Progenitor of Massive z > 6 Quasars
Document Type
Working Paper
Author
Larson, Rebecca L.; Finkelstein, Steven L.; Kocevski, Dale D.; Hutchison, Taylor A.; Trump, Jonathan R.; Haro, Pablo Arrabal; Bromm, Volker; Cleri, Nikko J.; Dickinson, Mark; Fujimoto, Seiji; Kartaltepe, Jeyhan S.; Koekemoer, Anton M.; Papovich, Casey; Pirzkal, Nor; Tacchella, Sandro; Zavala, Jorge A.; Bagley, Micaela; Behroozi, Peter; Champagne, Jaclyn B.; Cole, Justin W.; Jung, Intae; Morales, Alexa M.; Yang, Guang; Zhang, Haowen; Zitrin, Adi; Amorín, Ricardo O.; Burgarella, Denis; Casey, Caitlin M.; Ortiz, Óscar A. Chávez; Cox, Isabella G.; Chworowsky, Katherine; Fontana, Adriano; Gawiser, Eric; Grazian, Andrea; Grogin, Norman A.; Harish, Santosh; Hathi, Nimish P.; Hirschmann, Michaela; Holwerda, Benne W.; Juneau, Stéphanie; Leung, Gene C. K.; Lucas, Ray A.; McGrath, Elizabeth J.; Pérez-González, Pablo G.; Rigby, Jane R.; Seillé, Lise-Marie; Simons, Raymond C.; de la Vega, Alexander; Weiner, Benjamin J.; Wilkins, Stephen M.; Yung, L. Y. Aaron; Team, The CEERS
Source
The Astrophysical Journal Letters, 2023, Volume 953, Issue 2, id.L29, 26 pp
Subject
Language
Abstract
We report the discovery of an accreting supermassive black hole at z=8.679, in CEERS_1019, a galaxy previously discovered via a Ly$\alpha$-break by Hubble and with a Ly$\alpha$ 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$\alpha$ redshift. We detect a significant broad (FWHM~1200 km/s) component in the H$\beta$ 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 $\mu$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.
Comment: 26 pages, 14 figures, 6 tables, published in ApJL
Comment: 26 pages, 14 figures, 6 tables, published in ApJL