Статья

Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys

Jorryt MattheeDepartment of Physics, ETH Zürich, Wolfgang-Pauli-Strasse 27, Zürich, 8093, Switzerland; [email protected]Rohan P. NaiduMIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USAGabriel BrammerCosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen, Jagtvej 128, København N, DK-2200, DenmarkJohn ChisholmDepartment of Astronomy, The University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205, USAAnna–Christina EilersMIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USAAndy D. GouldingDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USAJenny E. GreeneDepartment of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USADaichi KashinoInstitute for Advanced Research, Nagoya University, Nagoya 464-8601, JapanIvo LabbéCentre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, VIC 3122, AustraliaS. J. LillyDepartment of Physics, ETH Zürich, Wolfgang-Pauli-Strasse 27, Zürich, 8093, Switzerland; [email protected]Ruari MackenzieDepartment of Physics, ETH Zürich, Wolfgang-Pauli-Strasse 27, Zürich, 8093, Switzerland; [email protected]Pascal A. OeschCosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen, Jagtvej 128, København N, DK-2200, DenmarkAndrea WeibelDepartment of Astronomy, University of Geneva, Chemin Pegasi 51, 1290 Versoix, SwitzerlandStijn WuytsDepartment of Physics, University of Bath, Claverton Down, Bath, BA2 7AY, UKMengyuan XiaoDepartment of Astronomy, University of Geneva, Chemin Pegasi 51, 1290 Versoix, SwitzerlandRongmon BordoloiDepartment of Physics, North Carolina State University, Raleigh, NC 27695, USAR. J. BouwensLeiden Observatory, Leiden University, NL-2300 RA Leiden, NetherlandsPieter van DokkumAstronomy Department, Yale University, 52 Hillhouse Avenue, New Haven, CT 06511, USAG. D. IllingworthDepartment of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064, USAIvan KramarenkoDepartment of Astronomy, University of Geneva, Chemin Pegasi 51, 1290 Versoix, SwitzerlandMichael V. MasedaDepartment of Astronomy, University of Wisconsin-Madison, 475 N. Charter Street, Madison, WI 53706 USACharlotte MasonCosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen, Jagtvej 128, København N, DK-2200, DenmarkR. A. MeyerDepartment of Astronomy, University of Geneva, Chemin Pegasi 51, 1290 Versoix, SwitzerlandErica J. NelsonDepartment for Astrophysical and Planetary Science, University of Colorado, Boulder, CO 80309, USANaveen A. ReddyDepartment of Physics and Astronomy, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, USAIrene ShivaeiCentro de Astrobiología (CAB), CSIC-INTA, Ctra. de Ajalvir km 4, Torrejón de Ardoz, E-28850, Madrid, SpainRobert A. SimcoeMIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USAMinghao YueMIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA

2024en

ABI

Аннотация

Abstract Characterizing the prevalence and properties of faint active galactic nuclei (AGNs) in the early Universe is key for understanding the formation of supermassive black holes (SMBHs) and determining their role in cosmic reionization. We perform a spectroscopic search for broad H α emitters at z ≈ 4–6 using deep JWST/NIRCam imaging and wide field slitless spectroscopy from the EIGER and FRESCO surveys. We identify 20 H α lines at z = 4.2–5.5 that have broad components with line widths from ∼1200–3700 km s −1 , contributing ∼30%–90% of the total line flux. We interpret these broad components as being powered by accretion onto SMBHs with implied masses ∼10 7–8 M ⊙ . In the UV luminosity range M UV,AGN+host = −21 to −18, we measure number densities of ≈10 −5 cMpc −3 . This is an order of magnitude higher than expected from extrapolating quasar UV luminosity functions (LFs). Yet, such AGN are found in only <1% of star-forming galaxies at z ∼ 5. The number density discrepancy is much lower when compared to the broad H α LF. The SMBH mass function agrees with large cosmological simulations. In two objects, we detect complex H α profiles that we tentatively interpret as caused by absorption signatures from dense gas fueling SMBH growth and outflows. We may be witnessing early AGN feedback that will clear dust-free pathways through which more massive blue quasars are seen. We uncover a strong correlation between reddening and the fraction of total galaxy luminosity arising from faint AGN. This implies that early SMBH growth is highly obscured and that faint AGN are only minor contributors to cosmic reionization.

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Идентификаторы

DOI: 10.3847/1538-4357/ad2345

Цитирования и источники

Цитирований: 2Использованных источников: 0

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