The Astrophysical Journal (Jan 2025)
UNCOVERing the High-redshift AGN Population among Extreme UV Line Emitters
- Helena Treiber,
- Jenny E. Greene,
- John R. Weaver,
- Tim B. Miller,
- Lukas J. Furtak,
- David J. Setton,
- Bingjie Wang,
- Anna de Graaff,
- Rachel Bezanson,
- Gabriel Brammer,
- Sam E. Cutler,
- Pratika Dayal,
- Robert Feldmann,
- Seiji Fujimoto,
- Andy D. Goulding,
- Vasily Kokorev,
- Ivo Labbe,
- Joel Leja,
- Danilo Marchesini,
- Themiya Nanayakkara,
- Erica Nelson,
- Richard Pan,
- Sedona H. Price,
- Jared Siegel,
- Katherine A. Suess,
- Katherine E. Whitaker
Affiliations
- Helena Treiber
- ORCiD
- Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; [email protected]
- Jenny E. Greene
- ORCiD
- Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; [email protected]
- John R. Weaver
- ORCiD
- Department of Astronomy, University of Massachusetts , Amherst, MA 01003, USA
- Tim B. Miller
- ORCiD
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics & Astronomy, Northwestern University , IL 60201, USA
- Lukas J. Furtak
- ORCiD
- Department of Physics, Ben-Gurion University of the Negev , P.O. Box 653, Beer-Sheva 8410501, Israel
- David J. Setton
- ORCiD
- Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; [email protected]
- Bingjie Wang
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Computational & Data Sciences, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Anna de Graaff
- ORCiD
- Max-Planck-Institut für Astronomie , Königstuhl 17, D-69117, Heidelberg, Germany
- Rachel Bezanson
- ORCiD
- Department of Physics & Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260, USA
- Gabriel Brammer
- ORCiD
- Cosmic Dawn Center (DAWN), Niels Bohr Institute, University of Copenhagen , Jagtvej 128, København N, DK-2200, Denmark
- Sam E. Cutler
- ORCiD
- Department of Astronomy, University of Massachusetts , Amherst, MA 01003, USA
- Pratika Dayal
- ORCiD
- Kapteyn Astronomical Institute, University of Groningen , P.O. Box 800, 9700 AV Groningen, The Netherlands
- Robert Feldmann
- ORCiD
- Department of Astrophysics, University of Zurich , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
- Seiji Fujimoto
- ORCiD
- Department of Astronomy, The University of Texas at Austin , Austin, TX 78712, USA
- Andy D. Goulding
- ORCiD
- Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; [email protected]
- Vasily Kokorev
- ORCiD
- Kapteyn Astronomical Institute, University of Groningen , P.O. Box 800, 9700 AV Groningen, The Netherlands
- Ivo Labbe
- ORCiD
- Centre for Astrophysics and Supercomputing, Swinburne University of Technology , Melbourne, VIC 3122, Australia
- Joel Leja
- ORCiD
- Department of Astronomy & Astrophysics, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Computational & Data Sciences, The Pennsylvania State University , University Park, PA 16802, USA; Institute for Gravitation and the Cosmos, The Pennsylvania State University , University Park, PA 16802, USA
- Danilo Marchesini
- ORCiD
- Department of Physics & Astronomy, Tufts University , MA 02155, USA
- Themiya Nanayakkara
- ORCiD
- Centre for Astrophysics and Supercomputing, Swinburne University of Technology , PO Box 218, Hawthorn, VIC 3122, Australia
- Erica Nelson
- ORCiD
- Department for Astrophysical and Planetary Science, University of Colorado , Boulder, CO 80309, USA
- Richard Pan
- ORCiD
- Department of Physics & Astronomy, Tufts University , 574 Boston Avenue, Medford, MA 02155, USA
- Sedona H. Price
- ORCiD
- Department of Physics & Astronomy and PITT PACC, University of Pittsburgh , Pittsburgh, PA 15260, USA
- Jared Siegel
- ORCiD
- Department of Astrophysical Sciences, Princeton University , 4 Ivy Lane, Princeton, NJ 08544, USA ; [email protected]
- Katherine A. Suess
- ORCiD
- Kavli Institute for Particle Astrophysics and Cosmology and Department of Physics, Stanford University , Stanford, CA 94305, USA
- Katherine E. Whitaker
- ORCiD
- Department of Astronomy, University of Massachusetts , Amherst, MA 01003, USA; Cosmic Dawn Center (DAWN) , Denmark
- DOI
- https://doi.org/10.3847/1538-4357/adc38f
- Journal volume & issue
-
Vol. 984,
no. 1
p. 93
Abstract
JWST has revealed diverse new populations of high-redshift ( z ∼ 4–11) active galactic nuclei (AGNs) and extreme star-forming galaxies that challenge current photoionization models. In this paper, we use rest-frame UV emission-line diagnostics to identify AGN candidates and other exceptional ionizing sources, complementing previous studies predominantly focused on broad-line AGNs. From a parent sample of 205 z _spec > 3 UNCOVER galaxies with NIRSpec/PRISM follow-up, we identify 12 galaxies with C IV , He II , and/or C III ] emission. Three of these galaxies also exhibit clear N III ] and/or N IV ] lines. Leveraging the combined rest-optical and UV coverage of PRISM, we limit the emission-line model space using the sample’s [O III ]/H β distribution, significantly decreasing the overlap between AGN and star formation models in the UV diagnostics. We then find that the five He II emitters are the strongest AGN candidates, with further support from two [Ne v ] detections and one X-ray detection from Chandra. Our Balmer line fits also reveal one new broad-line AGN at z = 6.87. We cannot robustly quantify the AGN fraction in this sample, but we note that close to 20% of M _* > 2 × 10 ^9 M _⊙ parent sample galaxies are AGN candidates. The lower-mass line emitters, which are consistent with both AGN and star-forming photoionization models, have more compact sizes and higher specific star formation rates than the parent sample. Higher-resolution and deeper data on these UV line emitters should provide much stronger constraints on the obscured AGN fraction at z > 3.
Keywords
