NGC 3227 Blinks: An Extreme Changing-look Event in a Seyfert Galaxy
Abstract We report a rapid optical changing-look event in the Seyfert galaxy NGC 3227: the optical continuum faded by ∼70%, and broad H β emission nearly disappeared within weeks before recovering within 2 months. Damped random walk simulations calibrated to the source’s normal variability show that such a decline is unlikely for stochastic accretion fluctuations. The optical decline coincides with an X-ray spectral hardening event detected by Swift, indicating additional line-of-sight absorption. During the dim state, reverberation mapping yields a clear 6–8 day lag between the continuum and broad H β , placing the obscurer interior to the broad-line region. Photoionization calculations require a fully ionized Compton-thick column with N H ≈ 1.5 × 10 24 cm −2 to reproduce the optical continuum suppression. Together, these observations demonstrate that compact, high-column-density obscurers interior to the broad-line region can produce extreme optical changing-look behavior on timescales of weeks.
Authors
- Feng-Na Fang (ORCID: https://orcid.org/0009-0009-9945-673X)
- Kaiwen Zhang (ORCID: https://orcid.org/0000-0002-5599-0190)
- Daniel Proga A (ORCID: https://orcid.org/0000-0002-6336-5125)
- K. Horne (ORCID: https://orcid.org/0000-0003-1728-0304)
- M. S. Brotherton (ORCID: https://orcid.org/0000-0002-1207-0909)
- Dong-Wei Bao (ORCID: https://orcid.org/0000-0003-2024-1648)
- Bi-Xuan Zhao (ORCID: https://orcid.org/0000-0002-1007-1991)
- Gerard A. Kriss (ORCID: https://orcid.org/0000-0002-2180-8266)
- Jian Wang (ORCID: https://orcid.org/0000-0003-1617-2002)
- Ming Xiao (ORCID: https://orcid.org/0000-0001-5981-6440)
- Chen Hu
- Pu Du
- Yan-Rong Li (ORCID: https://orcid.org/0000-0001-5841-9179)
Institutions
- University of Wyoming (US)
- Space Telescope Science Institute (US)
- University of Nevada, Reno (US)
- Chinese Academy of Sciences (CN)
- University of Chinese Academy of Sciences (CN)
Publication Details
- Journal
- The Astrophysical Journal Letters
- Published
- 2026-11-06
- DOI
- https://doi.org/10.3847/2041-8213/aeb6c3
- Primary Topic
- Astrophysical Phenomena and Observations
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- California Institute of Technology
- Northwestern University
- University of Washington
- University of Warwick
- Trinity College Dublin
- National Natural Science Foundation of China
- Stockholms Universitet
- National Science and Technology Major Project
- Deutsches Elektronen-Synchrotron
- Institut National de Physique Nucléaire et de Physique des Particules