Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys
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...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad2345 |
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| author | Jorryt Matthee Rohan P. Naidu Gabriel Brammer John Chisholm Anna-Christina Eilers Andy Goulding Jenny Greene Daichi Kashino Ivo Labbe Simon J. Lilly Ruari Mackenzie Pascal A. Oesch Andrea Weibel Stijn Wuyts Mengyuan Xiao Rongmon Bordoloi Rychard Bouwens Pieter van Dokkum Garth Illingworth Ivan Kramarenko Michael V. Maseda Charlotte Mason Romain A. Meyer Erica J. Nelson Naveen A. Reddy Irene Shivaei Robert A. Simcoe Minghao Yue |
| author_facet | Jorryt Matthee Rohan P. Naidu Gabriel Brammer John Chisholm Anna-Christina Eilers Andy Goulding Jenny Greene Daichi Kashino Ivo Labbe Simon J. Lilly Ruari Mackenzie Pascal A. Oesch Andrea Weibel Stijn Wuyts Mengyuan Xiao Rongmon Bordoloi Rychard Bouwens Pieter van Dokkum Garth Illingworth Ivan Kramarenko Michael V. Maseda Charlotte Mason Romain A. Meyer Erica J. Nelson Naveen A. Reddy Irene Shivaei Robert A. Simcoe Minghao Yue |
| author_sort | Jorryt Matthee |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-04-25T02:14:41Z |
| format | Article |
| id | doaj.art-281e2719ca694d0ba3610005b2e977cf |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-04-25T02:14:41Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-281e2719ca694d0ba3610005b2e977cf2024-03-07T10:03:16ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-01963212910.3847/1538-4357/ad2345Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST SurveysJorryt Matthee0https://orcid.org/0000-0003-2871-127XRohan P. Naidu1https://orcid.org/0000-0003-3997-5705Gabriel Brammer2https://orcid.org/0000-0003-2680-005XJohn Chisholm3https://orcid.org/0000-0002-0302-2577Anna-Christina Eilers4https://orcid.org/0000-0003-2895-6218Andy Goulding5https://orcid.org/0000-0003-4700-663XJenny Greene6https://orcid.org/0000-0002-5612-3427Daichi Kashino7https://orcid.org/0000-0001-9044-1747Ivo Labbe8https://orcid.org/0000-0002-2057-5376Simon J. Lilly9https://orcid.org/0000-0002-6423-3597Ruari Mackenzie10https://orcid.org/0000-0003-0417-385XPascal A. Oesch11https://orcid.org/0000-0001-5851-6649Andrea Weibel12https://orcid.org/0000-0001-8928-4465Stijn Wuyts13https://orcid.org/0000-0003-3735-1931Mengyuan Xiao14https://orcid.org/0000-0003-1207-5344Rongmon Bordoloi15https://orcid.org/0000-0002-3120-7173Rychard Bouwens16https://orcid.org/0000-0002-4989-2471Pieter van Dokkum17https://orcid.org/0000-0002-8282-9888Garth Illingworth18https://orcid.org/0000-0002-8096-2837Ivan Kramarenko19https://orcid.org/0000-0001-5346-6048Michael V. Maseda20https://orcid.org/0000-0003-0695-4414Charlotte Mason21https://orcid.org/0000-0002-3407-1785Romain A. Meyer22https://orcid.org/0000-0001-5492-4522Erica J. Nelson23https://orcid.org/0000-0002-7524-374XNaveen A. Reddy24https://orcid.org/0000-0001-9687-4973Irene Shivaei25https://orcid.org/0000-0003-4702-7561Robert A. Simcoe26https://orcid.org/0000-0003-3769-9559Minghao Yue27https://orcid.org/0000-0002-5367-8021Department of Physics , ETH Zürich, Wolfgang-Pauli-Strasse 27, Zürich, 8093, Switzerland ; jorryt.matthee@ist.ac.at; Institute of Science and Technology Austria (ISTA) , Am Campus 1, 3400 Klosterneuburg, AustriaMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USACosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen , Jagtvej 128, København N, DK-2200, DenmarkDepartment of Astronomy, The University of Texas at Austin , 2515 Speedway, Stop C1400, Austin, TX 78712-1205, USAMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USADepartment of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USADepartment of Astrophysical Sciences, Princeton University , Princeton, NJ 08544, USANational Astronomical Observatory of Japan , 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Institute for Advanced Research, Nagoya University , Nagoya 464-8601, JapanCentre for Astrophysics and Supercomputing, Swinburne University of Technology , Melbourne, VIC 3122, AustraliaDepartment of Physics , ETH Zürich, Wolfgang-Pauli-Strasse 27, Zürich, 8093, Switzerland ; jorryt.matthee@ist.ac.atDepartment of Physics , ETH Zürich, Wolfgang-Pauli-Strasse 27, Zürich, 8093, Switzerland ; jorryt.matthee@ist.ac.atCosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen , Jagtvej 128, København N, DK-2200, Denmark; Department of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, SwitzerlandDepartment of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, SwitzerlandDepartment of Physics, University of Bath , Claverton Down, Bath, BA2 7AY, UKDepartment of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, SwitzerlandDepartment of Physics, North Carolina State University , Raleigh, NC 27695, USALeiden Observatory, Leiden University , NL-2300 RA Leiden, NetherlandsAstronomy Department, Yale University , 52 Hillhouse Avenue, New Haven, CT 06511, USADepartment of Astronomy and Astrophysics, University of California , Santa Cruz, CA 95064, USADepartment of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, SwitzerlandDepartment of Astronomy, University of Wisconsin-Madison , 475 N. Charter Street, Madison, WI 53706 USACosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen , Jagtvej 128, København N, DK-2200, Denmark; Niels Bohr Institute, University of Copenhagen , Jagtvej 128, DK-2200 Copenhagen N, DenmarkDepartment of Astronomy, University of Geneva , Chemin Pegasi 51, 1290 Versoix, Switzerland; Max Planck Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, GermanyDepartment for Astrophysical and Planetary Science, University of Colorado , Boulder, CO 80309, USADepartment of Physics and Astronomy, University of California , Riverside, 900 University Avenue, Riverside, CA 92521, USASteward Observatory, University of Arizona , Tucson, AZ 85721, USA; Centro de Astrobiología (CAB) , CSIC-INTA, Ctra. de Ajalvir km 4, Torrejón de Ardoz, E-28850, Madrid, SpainMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USAMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USACharacterizing 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.https://doi.org/10.3847/1538-4357/ad2345High-redshift galaxiesQuasarsActive galactic nucleiReionization |
| spellingShingle | Jorryt Matthee Rohan P. Naidu Gabriel Brammer John Chisholm Anna-Christina Eilers Andy Goulding Jenny Greene Daichi Kashino Ivo Labbe Simon J. Lilly Ruari Mackenzie Pascal A. Oesch Andrea Weibel Stijn Wuyts Mengyuan Xiao Rongmon Bordoloi Rychard Bouwens Pieter van Dokkum Garth Illingworth Ivan Kramarenko Michael V. Maseda Charlotte Mason Romain A. Meyer Erica J. Nelson Naveen A. Reddy Irene Shivaei Robert A. Simcoe Minghao Yue Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys The Astrophysical Journal High-redshift galaxies Quasars Active galactic nuclei Reionization |
| title | Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys |
| title_full | Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys |
| title_fullStr | Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys |
| title_full_unstemmed | Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys |
| title_short | Little Red Dots: An Abundant Population of Faint Active Galactic Nuclei at z ∼ 5 Revealed by the EIGER and FRESCO JWST Surveys |
| title_sort | little red dots an abundant population of faint active galactic nuclei at z ∼ 5 revealed by the eiger and fresco jwst surveys |
| topic | High-redshift galaxies Quasars Active galactic nuclei Reionization |
| url | https://doi.org/10.3847/1538-4357/ad2345 |
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