Transient Relativistic Iron Emission Line from an X-Ray Flaring Supermassive Black Hole
Abstract We report the discovery of the first transient relativistic iron K α line in an active galactic nucleus (AGN), J1047+5907. The line was detected 21.5 days (rest frame) after an X-ray coronal flare was observed in 2008, and it exhibits significant broadening consistent with relativistic reflection from the accretion disk in the vicinity of the central supermassive black hole (SMBH). The line has a width of ∼300 eV, corresponding to a Keplerian velocity of 14,000 km s −1 , at a distance of 5–41 light-days from the SMBH, strongly implying that the observed coronal flare triggered the emergence of the line. This event provides rare direct evidence of the response of the accretion disk to impulsive coronal illumination and offers a new method to probe the SMBH and disk physics. The relativistic modeling favors a broadened line produced by distant reflection from an accretion disk around a rapidly spinning black hole viewed at an intermediate inclination, consistent with other observations. Systematic monitoring of type 1 AGN following strong X-ray flares may open a new observational window into the innermost regions of AGN, enabling constraints on the physics of SMBH and its accretion disk at different radii that are otherwise challenging to access.
Authors
- Peixin Zhu (ORCID: https://orcid.org/0000-0002-1333-147X)
- R. Silver (ORCID: https://orcid.org/0000-0001-6564-0517)
- Stefano Marchesi (ORCID: https://orcid.org/0000-0001-5544-0749)
- Javier A. García (ORCID: https://orcid.org/0000-0003-3828-2448)
- Zachary Stone (ORCID: https://orcid.org/0000-0002-8501-3518)
- Daniel Stern (ORCID: https://orcid.org/0000-0003-2686-9241)
- Qiaoya Wu (ORCID: https://orcid.org/0000-0003-4202-1232)
- A. Pizzetti (ORCID: https://orcid.org/0000-0001-6412-2312)
- Elias Kammoun (ORCID: https://orcid.org/0000-0002-0273-218X)
- Peter Boorman (ORCID: https://orcid.org/0000-0001-9379-4716)
- X. Zhao (ORCID: https://orcid.org/0000-0002-7791-3671)
- N. Torres-Albà (ORCID: https://orcid.org/0000-0003-3638-8943)
- F. A. Harrison
- Marco Ajello
- Qian Yang
- Yue Shen
- Francesca Civano
- Kirill V. Sokolovsky
- Erin Kara
Institutions
- California Institute of Technology (US)
- Goddard Space Flight Center (US)
- Jet Propulsion Laboratory (US)
- University of Illinois Urbana-Champaign (US)
- Center for Astrophysics Harvard & Smithsonian (US)
- European Southern Observatory (CL)
- Osservatorio di Astrofisica e Scienza dello Spazio
- University of Virginia (US)
- Massachusetts Institute of Technology (US)
- Clemson University (US)
- University of Bologna (IT)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2026-03-11
- DOI
- https://doi.org/10.3847/1538-4357/ae4482
- Primary Topic
- Astrophysical Phenomena and Observations
- Type
- article
- Field-Weighted Citation Impact
- 0.00