Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.12386/30090
Title: | The Quasar Main Sequence Explained by the Combination of Eddington Ratio, Metallicity, and Orientation | Authors: | Panda, Swayamtrupta MARZIANI, Paola Czerny, Bożena |
Issue Date: | 2019 | Journal: | THE ASTROPHYSICAL JOURNAL | Number: | 882 | Issue: | 2 | First Page: | 79 | Abstract: | We address the effect of orientation of the accretion disk plane and the geometry of the broad-line region (BLR) as part of an effort to understand the distribution of quasars in optical plane of the quasar main sequence. We utilize the photoionization code CLOUDY to model the BLR incorporating the grossly underestimated form factor (f). Treating the aspect of viewing angle appropriately, we confirm the dependence of the R <SUB>Fe II </SUB> sequence on L/{L}<SUB>Edd</SUB>} and on the related observational trends—as a function of the SED shape, cloud density, and composition, verified from prior observations. Sources with R <SUB>Fe II </SUB> in the range 1-2 (about 10% of all quasars, the so-called extreme Population A [xA] quasars) are explained as sources of high, and possibly extreme Eddington ratio along the R <SUB>Fe II </SUB> sequence. This result has important implications for the exploitation of xA sources as distance indicators for cosmology. Fe II emitters with R <SUB>Fe II </SUB> > 2 are very rare (<1% of all type 1 quasars). Our approach also explains the rarity of these highest Fe II emitters as extreme xA sources, and constrains the viewing angle ranges with increasing Hβ FWHM. | URI: | http://hdl.handle.net/20.500.12386/30090 | URL: | https://iopscience.iop.org/article/10.3847/1538-4357/ab3292 https://arxiv.org/abs/1905.01729 |
ISSN: | 0004-637X | DOI: | 10.3847/1538-4357/ab3292 | Bibcode ADS: | 2019ApJ...882...79P | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
1905.01729.pdf | postprint | 1.25 MB | Adobe PDF | View/Open |
Panda_2019_ApJ_882_79.pdf | Pdf editoriale | 4.48 MB | Adobe PDF | View/Open |
Page view(s)
48
checked on Apr 24, 2024
Download(s)
22
checked on Apr 24, 2024
Google ScholarTM
Check
Altmetric
Altmetric
Items in DSpace are published in Open Access, unless otherwise indicated.