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http://hdl.handle.net/20.500.12386/24387
Title: | A spectroscopic analysis of a sample of narrow-line Seyfert 1 galaxies selected from the Sloan Digital Sky Survey | Authors: | Cracco, V. Ciroi, S. Berton, M. Di Mille, F. FOSCHINI, LUIGI La Mura, G. Rafanelli, P. |
Issue Date: | 2016 | Journal: | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY | Number: | 462 | Issue: | 2 | First Page: | 1256 | Abstract: | We revisited the spectroscopic characteristics of narrow-line Seyfert 1 galaxies (NLS1s) by analysing a homogeneous sample of 296 NLS1s at redshift between 0.028 and 0.345, extracted from the Sloan Digital Sky Survey (SDSS-DR7) public archive. We confirm that NLS1s are mostly characterized by Balmer lines with Lorentzian profiles, lower black hole masses and higher Eddington ratios than classic broad-line Seyfert 1 (BLS1s), but they also appear to be active galactic nuclei (AGNs) contiguous with BLS1s and sharing with them common properties. Strong Fe II emission does not seem to be a distinctive property of NLS1s, as low values of Fe II/Hβ are equally observed in these AGNs. Our data indicate that Fe II and Ca II kinematics are consistent with the one of Hβ. On the contrary, O I λ8446 seems to be systematically narrower and it is likely emitted by gas of the broad-line region more distant from the ionizing source and showing different physical properties. Finally, almost all NLS1s of our sample show radial motions of the narrow-line region highly ionized gas. The mechanism responsible for this effect is not yet clear, but there are hints that very fast outflows require high continuum luminosities (>10<SUP>44</SUP> erg s<SUP>-1</SUP>) or high Eddington ratios (log (L<SUB>bol</SUB>/L<SUB>Edd</SUB>) > -0.1). | URI: | http://hdl.handle.net/20.500.12386/24387 | URL: | https://academic.oup.com/mnras/article/462/2/1256/2589433 https://arxiv.org/abs/1607.03438 |
ISSN: | 0035-8711 | DOI: | 10.1093/mnras/stw1689 | Bibcode ADS: | 2016MNRAS.462.1256C | Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista |
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stw1689.pdf | pdf editoriale | 2.19 MB | Adobe PDF | View/Open |
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