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标题：Properties of active galaxies at the extreme of Eigenvector 1
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作者：M. Śniegowska ; B. Czerny ; B. You 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2018
卷号：613
DOI：10.1051/0004-6361/201730433
语种：English
出版社：EDP Sciences
摘要：Context.Eigenvector 1 (EV1) is the formal parameter which allows the introduction of some order in the properties of the unobscured type 1 active galaxies.Aims.We aim to understand the nature of this parameter by analyzing the most extreme examples of quasars with the highest possible values of the corresponding eigenvaluesRFe.Methods.We selected the appropriate sources from the Sloan Digital Sky Survey (SDSS) and performed detailed modeling, including various templates for the Fe II pseudo-continuum and the starlight contribution to the spectrum.Results.Out of 27 sources withRFelarger than 1.3 and with the measurement errors smaller than 20% selected from the SDSS quasar catalog, only six sources were confirmed to have a high value ofRFe, defined as being above 1.3. All other sources have anRFeof approximately 1. Three of the highRFeobjects have a very narrow Hβline, below 2100 km s−1but three sources have broad lines, above 4500 km s−1, that do not seem to form a uniform group, differing considerably in black hole mass and Eddington ratio; they simply have a very similar EW([OIII]5007) line. Therefore, the interpretation of the EV1 remains an open issue.
关键词：Key wordsenquasars: emission linesaccretion, accretion disks