2026-05-22 中国科学院（CAS）
The standard AGN unification model and the eccentric disk AGN model. (Image by SHAO)
＜関連情報＞
- https://english.cas.cn/newsroom/research-news/202605/t20260522_1159819.shtml
- https://journals.aps.org/prd/abstract/10.1103/wwg4-ypvb
活動銀河核における偏心降着円盤 Eccentric accretion disks in active galactic nuclei
Hongping Deng
Physical Review D Published: 15 April, 2026
DOI: https://doi.org/10.1103/wwg4-ypvb
Abstract
We report that moderately eccentric flows around supermassive black holes (SMBHs), formed via either circumnuclear gas accretion or tidal disruption events, generate eccentricity cascades (from >0.8 to 0.2 outward), explaining multiwavelength emission and variability in active galactic nuclei (AGNs). The flows’ nonaxisymmetric temperature structure explains nonaxisymmetric dust sublimation fronts, distinct broad emission-line components, and their radial motions. The innermost broad-line region (BLR) links to the SMBH vicinity through highly eccentric streams that produce soft x-rays at periapsis. General relativistic precession further compresses these flows, generating a hard x-ray continuum near the SMBH. Precession of the eccentric flow drives optical/x-ray variability, reproducing the observed x-ray power spectral density and occasional x-ray quasiperiodic eruptions. We thus propose eccentric accretion disks as a physical AGN model that unifies the elusive BLRs and the x-ray corona. This model will enable detailed anatomy of AGNs and maximize their potential as cosmological standard candles.
