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  1. OA@INAF
  2. PRODOTTI RICERCA INAF
  3. 3 CONTRIBUTI IN ATTI DI CONVEGNO (Proceedings)
  4. 3.01 Contributi in Atti di convegno
Please use this identifier to cite or link to this item: http://hdl.handle.net/20.500.12386/28512
Title: Narrow-line Seyfert 1s: what is wrong in a name?
Authors: MARZIANI, Paola 
del Olmo, A.
D'Onofrio, M.
Dultzin, D.
Negrete, C. A.
Martínez-Aldama, M. L.
Bon, E.
Bon, N.
STIRPE, Giovanna Maria 
Issue Date: 2018
Journal: POS PROCEEDINGS OF SCIENCE 
Volume: Revisiting Narrow-Line Seyfert 1 Galaxies and their Place in the Universe
Number: 328
First Page: 2
Abstract: Narrow-line Seyfert 1s (NLSy1s) are an ill-defined class. Work done over the past 20 years as well as recent analyses show a continuity in properties (e.g., Balmer line profiles, blueshifts of high-ionization lines) between sources with FWHM above and below 2000 km/s, the defining boundary of NLSy1s. This finding alone suggests that comparisons between samples of NLSy1s and rest of broad-line AGNs are most likely biased. NLSy1s can be properly contextualized by their location on the quasar main sequence originally defined by Sulentic et al 2000. At one end, NLSy1s encompass sources with strong FeII emission and associated with high Eddington ratio that hold the promise of becoming useful distance indicators; at the other end, at least some of them are sources with broad profiles seen face-on. Any rigid FWHM limit gives rise to some physical ambiguity, as the FWHM of low-ionization lines depends in a complex way on mass, Eddington ratio, orientation, and luminosity. In addition, if the scaling derived from luminosity and virial dynamics applies to the broad line regions, NLSy1s at luminosity higher than 1E47 erg/s become physically impossible. Therefore, in a broader context, a proper subdivision of two distinct classes of AGNs and quasars may be achieved by the distinction between Pop. A and B with boundary at = 4000 km/s in samples at z < 1, or on the basis of spectrophotometric properties which may ultimately be related to differences in accretion modes if high-luminosity quasars are considered.
Conference Name: Revisiting Narrow-Line Seyfert 1 Galaxies and their Place in the Universe
Conference Place: Padova Botanical Garden, Italy
Conference Date: 9-13 April, 2018
URI: http://hdl.handle.net/20.500.12386/28512
URL: https://arxiv.org/pdf/1807.03003.pdf
https://pos.sissa.it/328/002/
https://pos.sissa.it/cgi-bin/reader/conf.cgi?confid=328
ISSN: 1824-8039
DOI: 10.22323/1.328.0002
Bibcode ADS: 2018rnls.confE...2M
Fulltext: open
Appears in Collections:3.01 Contributi in Atti di convegno

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