Isolating an Outflow Component in Single-Epoch Spectra of Quasars
Gaseous outflows appear to be a universal property of type-1 and type-2 active galactic nuclei (AGN). The main diagnostic is provided by emission features shifted to higher frequencies via the Doppler effect, implying that the emitting gas is moving toward the observer. However, beyond the presence...
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MDPI AG
2022-03-01
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Online Access: | https://www.mdpi.com/2075-4434/10/2/54 |
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author | Paola Marziani Alice Deconto-Machado Ascension Del Olmo |
author_facet | Paola Marziani Alice Deconto-Machado Ascension Del Olmo |
author_sort | Paola Marziani |
collection | DOAJ |
description | Gaseous outflows appear to be a universal property of type-1 and type-2 active galactic nuclei (AGN). The main diagnostic is provided by emission features shifted to higher frequencies via the Doppler effect, implying that the emitting gas is moving toward the observer. However, beyond the presence of blueshift, the observational signatures of the outflows are often unclear, and no established criteria exist to isolate the outflow contribution in the integrated, single-epoch spectra of type-1 AGN. The emission spectrum collected the typical apertures of long-slit spectroscopy or of fiber optics sample contributions over a broad range of spatial scales, making it difficult to analyze the line profiles in terms of different kinematical components. Nevertheless, hundred of thousands of quasars spectra collected at moderate resolution demand a proper analysis of the line profiles for proper dynamical modeling of the emitting regions. In this small contribution, we analyze several profiles of the <span style="font-variant: small-caps;">Hi</span> Balmer line <span style="font-variant: small-caps;">H</span><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>β</mi></semantics></math></inline-formula> from composite and individual spectra of sources radiating at moderate Eddington ratio (Population B). Features and profile shapes that might be traced to outflow due to narrow-line region gas are detected over a wide range of luminosity. |
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language | English |
last_indexed | 2024-03-09T10:36:25Z |
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spelling | doaj.art-9a2515869c21413482c8bd1405bc48982023-12-01T20:55:43ZengMDPI AGGalaxies2075-44342022-03-011025410.3390/galaxies10020054Isolating an Outflow Component in Single-Epoch Spectra of QuasarsPaola Marziani0Alice Deconto-Machado1Ascension Del Olmo2National Institute for Astrophysics (INAF), Astronomical Observatory of Padova, IT-35122 Padova, ItalyInstituto de Astrofisíca de Andalucía, IAA-CSIC, Glorieta de la Astronomia s/n, E-18008 Granada, SpainInstituto de Astrofisíca de Andalucía, IAA-CSIC, Glorieta de la Astronomia s/n, E-18008 Granada, SpainGaseous outflows appear to be a universal property of type-1 and type-2 active galactic nuclei (AGN). The main diagnostic is provided by emission features shifted to higher frequencies via the Doppler effect, implying that the emitting gas is moving toward the observer. However, beyond the presence of blueshift, the observational signatures of the outflows are often unclear, and no established criteria exist to isolate the outflow contribution in the integrated, single-epoch spectra of type-1 AGN. The emission spectrum collected the typical apertures of long-slit spectroscopy or of fiber optics sample contributions over a broad range of spatial scales, making it difficult to analyze the line profiles in terms of different kinematical components. Nevertheless, hundred of thousands of quasars spectra collected at moderate resolution demand a proper analysis of the line profiles for proper dynamical modeling of the emitting regions. In this small contribution, we analyze several profiles of the <span style="font-variant: small-caps;">Hi</span> Balmer line <span style="font-variant: small-caps;">H</span><inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>β</mi></semantics></math></inline-formula> from composite and individual spectra of sources radiating at moderate Eddington ratio (Population B). Features and profile shapes that might be traced to outflow due to narrow-line region gas are detected over a wide range of luminosity.https://www.mdpi.com/2075-4434/10/2/54active galactic nucleioptical spectroscopyionized gasbroad line region |
spellingShingle | Paola Marziani Alice Deconto-Machado Ascension Del Olmo Isolating an Outflow Component in Single-Epoch Spectra of Quasars Galaxies active galactic nuclei optical spectroscopy ionized gas broad line region |
title | Isolating an Outflow Component in Single-Epoch Spectra of Quasars |
title_full | Isolating an Outflow Component in Single-Epoch Spectra of Quasars |
title_fullStr | Isolating an Outflow Component in Single-Epoch Spectra of Quasars |
title_full_unstemmed | Isolating an Outflow Component in Single-Epoch Spectra of Quasars |
title_short | Isolating an Outflow Component in Single-Epoch Spectra of Quasars |
title_sort | isolating an outflow component in single epoch spectra of quasars |
topic | active galactic nuclei optical spectroscopy ionized gas broad line region |
url | https://www.mdpi.com/2075-4434/10/2/54 |
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