Chandra Detects Low-luminosity Active Galactic Nucleus with <i>M</i> <sub>BH</sub> = 10<sup>4</sup>–10<sup>6</sup> <i> M</i> <sub>⊙</sub> in Nearby (<i>z</i> < 0.5) Dwarf and Star-forming Galaxies
Abstract We searched the Chandra and XMM archives for 900 Green Pea galaxies to identify signs of active galactic nuclei (AGN). Green peas are low-mass, emission-line galaxies that resemble high-redshift dwarf galaxies. From 29 observations, we detected X-rays in nine galaxies with signal-to-noise ratio > 3. These X-ray sources also show He ii and broad H α emissions, suggesting winds, though the weak correlation between their line widths implies that the He ii emission is not from super-Eddington accretors. The ratio of X-ray luminosity to star formation rate aligns with an anticorrelation with metallicity for most detected sources, pointing to ultraluminous X-ray sources as likely contributors. The X-ray emission exceeds what stellar processes can produce, supporting the existence of low-luminosity AGN. Using the broad H α emission lines, we infer black hole masses ranging from 10 4 to 10 6 M ⊙ in these sources. Since Green Peas are significant Lyman continuum leakers, these AGN may have played a role in cosmic reionization.
Authors
- Zhen-Ya Zheng (ORCID: https://orcid.org/0000-0002-9634-2923)
- James E. Rhoads (ORCID: https://orcid.org/0000-0002-1501-454X)
- Junxian Wang (ORCID: https://orcid.org/0000-0002-4419-6434)
- Santosh Harish (ORCID: https://orcid.org/0000-0003-0129-2079)
- Keunho Kim (ORCID: https://orcid.org/0000-0001-6505-0293)
- Julissa Sarmiento (ORCID: https://orcid.org/0000-0002-5293-3975)
- Sangeeta Malhotra (ORCID: https://orcid.org/0000-0002-9226-5350)
- M. Singha (ORCID: https://orcid.org/0000-0001-5687-1516)
- L. Y. Aaron Yung (ORCID: https://orcid.org/0000-0003-3466-035X)
- Jia-Lai Kang (ORCID: https://orcid.org/0000-0003-2280-2904)
- Ruqiu Lin
Institutions
- California Institute of Technology (US)
- University of Science and Technology of China (CN)
- Space Telescope Science Institute (US)
- Goddard Space Flight Center (US)
- Rochester Institute of Technology (US)
- University of America (US)
- University of Pittsburgh (US)
- Shanghai Astronomical Observatory (CN)
- Université Bourgogne Franche-Comté (FR)
- University of Chinese Academy of Sciences (CN)
- Infrared Processing and Analysis Center (US)
- Deleted Institution
- Catholic University of America (US)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2025-05-07
- DOI
- https://doi.org/10.3847/1538-4357/adb979
- Citations
- 2
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 2.31
Funders
- National Science Foundation
- Smithsonian Institution
- National Aeronautics and Space Administration
- Alfred P. Sloan Foundation
- Yale University
- Carnegie Institution of Washington
- Ohio State University
- Natural Science Foundation of Shanghai
- Harvard University
- University of Utah
- Johns Hopkins University
- New Mexico State University
- Space Telescope Science Institute
- École Polytechnique Fédérale de Lausanne
- National Natural Science Foundation of China
- University of Toronto
- Universidad Nacional Autónoma de México
- Yunnan University
- Nanjing University
- China National Textile and Apparel Council
- Leibniz-Institut für Astrophysik Potsdam
- Max-Planck-Institut für Astronomie
- University of Illinois at Urbana-Champaign
- Goddard Space Flight Center
- University of Colorado Boulder
- Smithsonian Astrophysical Observatory
- Leibniz-Gemeinschaft
- National Astronomical Observatories, Chinese Academy of Sciences