AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548
Many active galactic nuclei (AGN) show strong variability of the optical continuum. Since the line flux, profile shapes and intensity ratios are changing, we analyze the variability patterns and possible periodicity of Type 1 AGN NGC 5548, using the Eigenvector 1 (EV1) diagram in different variabili...
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doaj-7c652412cf824d678caa2bfbf851e8d92020-11-24T22:51:13ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2018-01-01510.3389/fspas.2018.00003326556AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548Nataša Bon0Edi Bon1Paola Marziani2Astronomical Observatory, Belgrade, SerbiaAstronomical Observatory, Belgrade, SerbiaOsservatorio Astronomico di Padova (INAF), Padua, ItalyMany active galactic nuclei (AGN) show strong variability of the optical continuum. Since the line flux, profile shapes and intensity ratios are changing, we analyze the variability patterns and possible periodicity of Type 1 AGN NGC 5548, using the Eigenvector 1 (EV1) diagram in different variability states, taking advantage of very long term monitoring campaign data. The preliminary results suggest that NGC 5548—a highly variable object that over several decades has shown large amplitude continuum fluctuations and flaring behavior—remains Pop B. This means that the range in Eddington ratio, even when the source is in a bright state, remains consistent with the value of the low accreting Pop B. We inspected EV 1 parameters of a single object though long term monitoring, assuming an inclination and black hole mass to be constant during the observational time. Our results imply that the main driver for the variations along the EV 1 diagram could be dimensionless accretion rate. If so, then it appears that the source never crossed the boundary for structural changes, indicatively placed at L/LEdd ~ 0.2.http://journal.frontiersin.org/article/10.3389/fspas.2018.00003/fullgalaxies:active-galaxiesquasar:supermassive black holesquasar:emission linesline:profilesquasar: individual (NGC 5548) |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Nataša Bon Edi Bon Paola Marziani |
spellingShingle |
Nataša Bon Edi Bon Paola Marziani AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548 Frontiers in Astronomy and Space Sciences galaxies:active-galaxies quasar:supermassive black holes quasar:emission lines line:profiles quasar: individual (NGC 5548) |
author_facet |
Nataša Bon Edi Bon Paola Marziani |
author_sort |
Nataša Bon |
title |
AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548 |
title_short |
AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548 |
title_full |
AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548 |
title_fullStr |
AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548 |
title_full_unstemmed |
AGN Broad Line Region Variability in the Context of Eigenvector 1: Case of NGC 5548 |
title_sort |
agn broad line region variability in the context of eigenvector 1: case of ngc 5548 |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Astronomy and Space Sciences |
issn |
2296-987X |
publishDate |
2018-01-01 |
description |
Many active galactic nuclei (AGN) show strong variability of the optical continuum. Since the line flux, profile shapes and intensity ratios are changing, we analyze the variability patterns and possible periodicity of Type 1 AGN NGC 5548, using the Eigenvector 1 (EV1) diagram in different variability states, taking advantage of very long term monitoring campaign data. The preliminary results suggest that NGC 5548—a highly variable object that over several decades has shown large amplitude continuum fluctuations and flaring behavior—remains Pop B. This means that the range in Eddington ratio, even when the source is in a bright state, remains consistent with the value of the low accreting Pop B. We inspected EV 1 parameters of a single object though long term monitoring, assuming an inclination and black hole mass to be constant during the observational time. Our results imply that the main driver for the variations along the EV 1 diagram could be dimensionless accretion rate. If so, then it appears that the source never crossed the boundary for structural changes, indicatively placed at L/LEdd ~ 0.2. |
topic |
galaxies:active-galaxies quasar:supermassive black holes quasar:emission lines line:profiles quasar: individual (NGC 5548) |
url |
http://journal.frontiersin.org/article/10.3389/fspas.2018.00003/full |
work_keys_str_mv |
AT natasabon agnbroadlineregionvariabilityinthecontextofeigenvector1caseofngc5548 AT edibon agnbroadlineregionvariabilityinthecontextofeigenvector1caseofngc5548 AT paolamarziani agnbroadlineregionvariabilityinthecontextofeigenvector1caseofngc5548 |
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1725670754936160256 |