Integrated models for the narrow emission line region of active galactic nuclei

1988 ◽  
Vol 324 ◽  
pp. 683 ◽  
Author(s):  
S. M. Viegas-Aldrovandi ◽  
R. B. Gruenwald
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Integrated Models ◽  
Line Region ◽  
Narrow Emission

scholarly journals Molecular hydrogen and [Fe ii] in active galactic nuclei – III. Low-ionization nuclear emission-line region and star-forming galaxies

2013 ◽  
Vol 430 (3) ◽  
pp. 2002-2017 ◽  
Author(s):  
R. Riffel ◽  
A. Rodríguez-Ardila ◽  
I. Aleman ◽  
M. S. Brotherton ◽  
M. G. Pastoriza ◽  
...  
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Molecular Hydrogen ◽  
Galactic Nuclei ◽  
Star Forming ◽  
Line Region

scholarly journals Velocity Diagnostics of the Broad Emission-Line Region of Active Galactic Nuclei

1997 ◽  
Vol 159 ◽  
pp. 175-178 ◽  
Author(s):  
Brian Espey
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Nuclear Region ◽  
Driving Mechanisms ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line ◽  
Ongoing Project

AbstractWe present a brief review of emission-line velocity differences, and describe an ongoing project to determine the driving mechanisms responsible. We conclude with a brief outline of the use of velocity differences as probes of the conditions in the nuclear region of AGNs.

scholarly journals Emission Line Region in a sample of 12 active galactic nuclei

2004 ◽  
Vol 2004 (IAUS222) ◽  
pp. 355-356
Author(s):  
L. C. Popovic ◽  
E. Mediavilla ◽  
E. Bon ◽  
D. Ilic
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Line Region

Narrow emission-line profiles of active galactic nuclei

1989 ◽  
Vol 343 ◽  
pp. 78 ◽  
Author(s):  
M. Contini ◽  
S. M. Viegas-Aldrovandi
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Line Profiles ◽  
Narrow Emission

scholarly journals Constraints on the outer radius of the broad emission line region of active galactic nuclei

2014 ◽  
Vol 439 (1) ◽  
pp. 1051-1062 ◽  
Author(s):  
Hermine Landt ◽  
Martin J. Ward ◽  
Martin Elvis ◽  
Margarita Karovska
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Outer Radius ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line

scholarly journals The near-infrared broad emission line region of active galactic nuclei - II. The 1-μm continuum

2011 ◽  
Vol 414 (1) ◽  
pp. 218-240 ◽  
Author(s):  
Hermine Landt ◽  
Martin Elvis ◽  
Martin J. Ward ◽  
Misty C. Bentz ◽  
Kirk T. Korista ◽  
...  
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Near Infrared ◽  
Galactic Nuclei ◽  
Broad Emission ◽  
Line Region ◽  
Broad Emission Line

scholarly journals Fotometria BVRI da galáxia M49 (NGC 4472): Reduções IRAF e MaxIm DL

2019 ◽  
Author(s):  
Vitor De Oliveira Silva
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Galactic Nuclei ◽  
Line Region

A galáxia Messier 49 (M49, NGC 4472), descoberta por Charles Messier em 1771, éuma galáxia com morfologia elíptica gigante, E2, mas também é classificada como umagaláxia lenticular, S0, (De Vaucouleurs et al. 1991), localizada na constelação deVirgem (ver Figura 1). Foi a primeira galáxia membro do aglomerado de Virgem a serdescoberta e é uma das mais brilhante deste sistema, com magnitude na banda B =9,37±0,06 (De Vaucouleurs et al. 1991). Representa um objeto extragaláctico (z =0,003272±0,00017) com velocidade de recessão de 981±5 km/s. É classficada comnúcleo ativo (AGN – Active Galactic Nuclei), do tipo Seyfert2. Uma classificaçãoLINER (Low-Ionization Nuclear Emission Line Region) também é sugerida. Possucoordenadas equatoriais  = 12h29m46,7s e  = 00’02’’.Fotometria CCD (BVRI) de objetos extensos representa uma linha de pesquisa que estásendo desenvolvida com o telescópio CDK20 (Corrected Dall-Kirkham Astrographtelescope, de 20 polegadas – 50,8cm de diâmetro), instalado no ObservatórioAstronômico Antares (OAA). Apesar de ser um objeto bem estudado na literatura comas técnicas de fotometria e espectroscopia (e.g., Foster et al. (2011), Kim (2010),Sanchez-Blazquez et al. (2007), Michard (1985), King (1978)), em diversoscomprimentos de onda do espectro eletromagnético, M49 representa um excelenteexemplo para iniciar os conceitos de fotometria superficial para os estudantes deIniciação Científica.Em geral, o pacote IRAF (Image Reduction and Analysis Facility), de domínio público,consiste de um sistema de softwares construído para a redução e análise de dadosastronômicos, e vem sendo empregado sistematicamente em nossas reduçõesfotométricas e/ou espectoscópicas. No entanto, apesar da sua ampla validade já assegurapela comunidade astronômica, iremos utilizar um pacote alternativo, MaxIm DL,desenvolvido pela Cyanogen Imaging®. Portanto, uma avaliação quanto a performancepermitirá avaliar o mesmo para o uso em futuras reduções fotométricas, não apenas deobjetos extensos, mas também de estrelas, aglomerados e objetos do Sistema Solar, emparticular, asteróides.

scholarly journals State-of-the-art AGN SEDs for photoionization models: BLR predictions confront the observations

2020 ◽  
Vol 494 (4) ◽  
pp. 5917-5922 ◽  
Author(s):  
G J Ferland ◽  
C Done ◽  
C Jin ◽  
H Landt ◽  
M J Ward
Keyword(s):  
Emission Line ◽  
Active Galactic Nuclei ◽  
Spectral Energy Distribution ◽  
Galactic Nuclei ◽  
Spectral Energy ◽  
X Ray ◽  
Line Region ◽  
Energy Conserving ◽  
Far Ultraviolet ◽  
New Generation

ABSTRACT The great power offered by photoionization models of active galactic nuclei emission line regions has long been mitigated by the fact that very little is known about the spectral energy distribution (SED) between the Lyman limit, where intervening absorption becomes a problem, and  0.3 keV, where soft X-ray observations become possible. The emission lines themselves can, to some degree, be used to probe the SED, but only in the broadest terms. This paper employs a new generation of theoretical SEDs that are internally self-consistent, energy conserving, and tested against observations, to infer properties of the emission-line regions. The SEDs are given as a function of the Eddington ratio, allowing emission-line correlations to be investigated on a fundamental basis. We apply the simplest possible tests, based on the foundations of photoionization theory, to investigate the implications for the geometry of the emission-line region. The SEDs become more far-ultraviolet bright as the Eddington ratio increases, so the equivalent widths of recombination lines should also become larger, an effect that we quantify. The observed lack of correlation between Eddington ratio and equivalent width shows that the cloud covering factor must decrease as Eddington ratio increases. This would be consistent with recent models proposing that the broad-line region is a failed dusty wind off the accretion disc.

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