2010/09/10 by Xiao-Bo Dong, Luis C. Ho, Jian-Guo Wang +4
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Doubly ionized oxygen #Emission spectrum #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geometry #Line (geometry) #Luminosity #Physics #QSOS #Quasar #Redshift #Sky #Spectral line #Stellar, planetary, and galactic studies #Torus #Type (biology) #astro-ph.GA
paper · pdf · doi:10.1088/2041-8205/721/2/l143
published as The Astrophysical Journal Letters, 721, L143-L147 (2010) · This Letter is separated from arXiv:0903.5020 (sumbitted to ApJ), with more tests on the robustness of the detection of narrow Fe II emission as well as more quantitative details and figures about narrow Fe II emission lines in AGNs. The implementation of the analytical narrow and broad Fe II templates in IDL is available at http://staff.ustc.edu.cn/~xbdong/Data_Release/FeII/Template/
openalex publication_date 2010/09/10 · arxiv created 2010/09/12 · arxiv updated 2010/09/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
From detailed spectral analysis of a large sample of low-redshift active galactic nuclei (AGNs) selected from the Sloan Digital Sky Survey, we demonstrate—statistically for the first time—that narrow optical Fe ii emission lines, both permitted and forbidden, are prevalent in type 1 AGNs. Remarkably, these optical lines are completely absent in type 2 AGNs, across a wide luminosity range, from Seyfert 2 galaxies to type 2 quasars. We suggest that the narrow Fe ii -emitting gas is confined to a disk-like geometry in the innermost regions of the narrow-line region on physical scales smaller than the obscuring torus.