The Iwasawa–Taniguchi Effect in Compton-thick Seyfert 2 Galaxies with Extended Hard X-Ray Emission
Year: 2025
Type: article
Abstract: The anti-correlation between the equivalent width of the neutral narrow Fe Kα line and the 2–10 keV luminosity (the Iwasawa–Taniguchi effect) in the nuclear regions of active galactic nuclei has been debated in recent years. With the high angular resolution of Chandra, an increasing number of Compton-thick sources have been found to show extended narrow Fe Kα emission on scales from tens of parsecs to kiloparsecs, attributed to reprocessing of nuclear radiation by surrounding Compton-thick material. We analyze eight Compton-thick sources with prominent extended Fe Kα emission. We confirm the Iwasawa–Taniguchi effect in the extended component relative to the reflection spectrum, with a steeper slope, indicating reduced production efficiency of neutral Fe Kα photon outside the nucleus. Both the reflection spectrum and Fe Kα luminosities correlate positively with intrinsic AGN luminosity, suggesting that the nucleus drives the extended emission. Finally, we find a linear relationship between redshift and the equivalent width of the nuclear Fe Kα line, with no such trend in the extended component.
Source: Universe
Authors: Jia Chen, Huili Yi, Chengchao Liu, Shenfang Ye, Shuangxi Yi
Institutions: Linyi University, Qufu Normal University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,930
Award: G6324733455
OpenAlex ID: W4415359063