Work

Periodic variations in the first and second moments of broad Balmer emission lines from central accretion disks

Year: 2025

Type: article

Abstract: Broad emission line regions (BLRs) lying in central accretion disks are widely accepted to explain the unique double-peaked broad emission lines in active galactic nuclei (double-peaked BLAGNs). Accepting the accretion disk origin, we theoretically simulated and determined the periodic variations in the central wavelength λ0 (the first moment) and line width σ (the second moment) of double-peaked broad emission lines. Furthermore, through theoretically simulated periodicities of Tλ0 and Tσ for variations in λ0 and σ, a periodicity ratio Rfs of Tλ0 to Tσ of about 2 was applied to support the hypothesis that the spiral arms are preferred in BLRs in central accretion disks. Then, we determined the periodic variations in λ0 and σ and showed them in the known double-peaked BLAGN NGC 1097. This led to the parameter Rfs ∼ 2, which can be applied as a clue to support the hypothesis that the spiral arm structure in disk-like BLRs in the central accretion disk is the most compelling interpretation of the variability in the double-peaked broad Hα in NGC 1097. The results provide clean criteria for testing the accretion disk origins of double-peaked broad emission lines in AGN.

Source: Astronomy and Astrophysics

DOI: 10.1051/0004-6361/202554136

Author: XueGuang Zhang

Institution: Guangxi University

Language: English

Topic: Galaxies: Formation, Evolution, Phenomena

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,865