2002/10/31 by H. D. Tran, Hien D. Tran · 163 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Isotropy #Physics #Spectral line #Star formation #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/345473
published in The Astrophysical Journal 583(2), 632-648 (IOP Publishing) · 15 pages with embedded figs, ApJ in press, vol. 583, 2003 Feb. 1. v2: minor corrections to text, some typos removed; updated reference list: some added, some removed
arxiv created 2002/11/14 · openalex publication_date 2003/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We extend the analysis presented in Paper I of a spectropolarimetric survey of the CfA and 12 μm samples of Seyfert 2 galaxies (S2s). We confirm that polarized (hidden) broad-line region (HBLR) S2s tend to have hotter circumnuclear dust temperatures, show mid-IR spectra more characteristic of Seyfert 1 galaxies (S1s), and are intrinsically more luminous than non-HBLR S2s. The levels of obscuration and circumnuclear star formation, however, appear to be similar between HBLR and non-HBLR S2 galaxies, based on an examination of various observational indicators. HBLR S2s, on average, share many similar large-scale, presumably isotropic, characteristics with S1s, as would be expected if the unified model is correct, while non-HBLR S2s generally do not. The active nuclear engines of non-HBLR S2s, then, appear to be truly weaker than HBLR S2s, which in turn are fully consistent with being S1s viewed from another direction. There is also evidence that the fraction of detected HBLRs increases with the radio power of the active galactic nucleus. Thus, all S2 galaxies may not be intrinsically similar in nature, and we speculate that evolutionary processes may be at work.