TY - JOUR
T1 - Hidden Little Monsters
T2 - Spectroscopic Identification of Low-mass, Broad-line AGNs at z > 5 with CEERS
AU - Kocevski, Dale D.
AU - Onoue, Masafusa
AU - Inayoshi, Kohei
AU - Trump, Jonathan R.
AU - Haro, Pablo Arrabal
AU - Grazian, Andrea
AU - Dickinson, Mark
AU - Finkelstein, Steven L.
AU - Kartaltepe, Jeyhan S.
AU - Hirschmann, Michaela
AU - Aird, James
AU - Holwerda, Benne W.
AU - Fujimoto, Seiji
AU - Juneau, Stéphanie
AU - Amorín, Ricardo O.
AU - Backhaus, Bren E.
AU - Bagley, Micaela B.
AU - Barro, Guillermo
AU - Bell, Eric F.
AU - Bisigello, Laura
AU - Calabrò, Antonello
AU - Cleri, Nikko J.
AU - Cooper, M. C.
AU - Ding, Xuheng
AU - Grogin, Norman A.
AU - Ho, Luis C.
AU - Hutchison, Taylor A.
AU - Inoue, Akio K.
AU - Jiang, Linhua
AU - Jones, Brenda
AU - Koekemoer, Anton M.
AU - Li, Wenxiu
AU - Li, Zhengrong
AU - McGrath, Elizabeth J.
AU - Molina, Juan
AU - Papovich, Casey
AU - Pérez-González, Pablo G.
AU - Pirzkal, Nor
AU - Wilkins, Stephen M.
AU - Yang, Guang
AU - Aaron Yung, L. Y.
N1 - Funding Information:
This work is supported by NASA grants JWST-ERS-01345 and JWST-AR-02446 and based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. The specific observations analyzed can be accessed via doi:10.17909/z7p0-8481. This work also made use of the Rainbow Cosmological Surveys Database, which is operated by the Centro de Astrobiología (CAB/INTA), partnered with the University of California Observatories at Santa Cruz (UCO/Lick,UCSC).
Funding Information:
A.G. acknowledges financial contribution from the grant PRIN INAF 2019 (RIC) 1.05.01.85.09, “New Light on the Intergalactic Medium (NewIGM),” and support from PRIN MIUR project “Black Hole Winds and the Baryon Life Cycle of Galaxies: The Stone-Guest at the Galaxy Evolution Supper,” contract 2017-PH3WAT.
Funding Information:
We also acknowledge support from the National Natural Science Foundation of China (12073003, 12150410307, 12003003, 11721303, 11991052, 11950410493) and the China Manned Space Project Nos. CMS-CSST-2021-A04 and CMS-CSST-2021-A06. P.G.P.-G. acknowledges support from Spanish Ministerio de Ciencia e Innovación MCIN/AEI/10.13039/501100011033 through grant PGC2018-093499-B-I00.
Funding Information:
This work is supported by NASA grants JWST-ERS-01345 and JWST-AR-02446 and based on observations made with the NASA/ESA/CSA James Webb Space Telescope. The data were obtained from the Mikulski Archive for Space Telescopes at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-03127 for JWST. The specific observations analyzed can be accessed via doi: 10.17909/z7p0-8481 . This work also made use of the Rainbow Cosmological Surveys Database, which is operated by the Centro de Astrobiología (CAB/INTA), partnered with the University of California Observatories at Santa Cruz (UCO/Lick,UCSC).
Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/9
Y1 - 2023/9
N2 - We report on the discovery of two low-luminosity, broad-line active galactic nuclei (AGNs) at z > 5 identified using JWST NIRSpec spectroscopy from the Cosmic Evolution Early Release Science (CEERS) survey. We detect broad Hα emission in the spectra of both sources, with FWHM of 2060 ± 290 km s−1 and 1800 ± 200 km s−1, resulting in virial black hole (BH) masses that are 1-2 dex below those of existing samples of luminous quasars at z > 5. The first source, CEERS 2782 at z = 5.242, is 2-3 dex fainter than known quasars at similar redshifts and was previously identified as a candidate low-luminosity AGN based on its morphology and rest-frame optical spectral energy distribution (SED). We measure a BH mass of M BH = (1.3 ± 0.4) × 107 M ⊙, confirming that this AGN is powered by the least massive BH known in the Universe at the end of cosmic reionization. The second source, CEERS 746 at z = 5.624, is inferred to be a heavily obscured, broad-line AGN caught in a transition phase between a dust-obscured starburst and an unobscured quasar. We estimate its BH mass to be in the range of M BH ≃ (0.9-4.7) × 107 M ⊙, depending on the level of dust obscuration assumed. We perform SED fitting to derive host stellar masses, M ⋆, allowing us to place constraints on the BH-galaxy mass relationship in the lowest mass range yet probed in the early Universe. The M BH/M ⋆ ratio for CEERS 2782, in particular, is consistent with or higher than the empirical relationship seen in massive galaxies at z = 0. We examine the narrow emission line ratios of both sources and find that their location on the BPT and OHNO diagrams is consistent with model predictions for moderately low metallicity AGNs with Z/Z ⊙ ≃ 0.2-0.4. The spectroscopic identification of low-luminosity, broad-line AGNs at z > 5 with M BH ≃ 107 M ⊙ demonstrates the capability of JWST to push BH masses closer to the range predicted for the BH seed population and provides a unique opportunity to study the early stages of BH-galaxy assembly.
AB - We report on the discovery of two low-luminosity, broad-line active galactic nuclei (AGNs) at z > 5 identified using JWST NIRSpec spectroscopy from the Cosmic Evolution Early Release Science (CEERS) survey. We detect broad Hα emission in the spectra of both sources, with FWHM of 2060 ± 290 km s−1 and 1800 ± 200 km s−1, resulting in virial black hole (BH) masses that are 1-2 dex below those of existing samples of luminous quasars at z > 5. The first source, CEERS 2782 at z = 5.242, is 2-3 dex fainter than known quasars at similar redshifts and was previously identified as a candidate low-luminosity AGN based on its morphology and rest-frame optical spectral energy distribution (SED). We measure a BH mass of M BH = (1.3 ± 0.4) × 107 M ⊙, confirming that this AGN is powered by the least massive BH known in the Universe at the end of cosmic reionization. The second source, CEERS 746 at z = 5.624, is inferred to be a heavily obscured, broad-line AGN caught in a transition phase between a dust-obscured starburst and an unobscured quasar. We estimate its BH mass to be in the range of M BH ≃ (0.9-4.7) × 107 M ⊙, depending on the level of dust obscuration assumed. We perform SED fitting to derive host stellar masses, M ⋆, allowing us to place constraints on the BH-galaxy mass relationship in the lowest mass range yet probed in the early Universe. The M BH/M ⋆ ratio for CEERS 2782, in particular, is consistent with or higher than the empirical relationship seen in massive galaxies at z = 0. We examine the narrow emission line ratios of both sources and find that their location on the BPT and OHNO diagrams is consistent with model predictions for moderately low metallicity AGNs with Z/Z ⊙ ≃ 0.2-0.4. The spectroscopic identification of low-luminosity, broad-line AGNs at z > 5 with M BH ≃ 107 M ⊙ demonstrates the capability of JWST to push BH masses closer to the range predicted for the BH seed population and provides a unique opportunity to study the early stages of BH-galaxy assembly.
UR - https://www.scopus.com/pages/publications/85169892286
U2 - 10.3847/2041-8213/ace5a0
DO - 10.3847/2041-8213/ace5a0
M3 - Article
AN - SCOPUS:85169892286
SN - 2041-8205
VL - 954
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L4
ER -