arXiv: Astrophysics
Read

Emission Line Properties of Seyfert 2 Nuclei

Publication Date Oct 26, 2005

Abstract

We present a study of the global properties of Joguet's sample of 65 Seyfert 2 galaxies. We use the population synthesis models of our Paper II to derive `pure' emission-line spectra, and thus explore the statistical properties of the nuclear nebular components and their relation to the stellar populations. We find that the emission line clouds suffer substantially more extinction than the starlight, and confirm the correlations between stellar and nebular velocity dispersions and between emission line luminosity and velocity dispersions. Nuclear luminosities correlate with stellar velocity dispersions. Removing the contribution of young stars to the optical continuum produces a tighter and steeper relation, $L \propto \sigma_\star^4$, consistent with the Faber-Jackson law. Emission line ratios indicative of the gas excitation such as [OIII]/H$\beta$ and [OIII]/[OII] are statistically smaller for Seyferts with significant star-formation, implying that ionization by massive stars is responsible for a substantial, and sometimes even a dominant, fraction of the H$\beta$ and [OII] fluxes. We use our models to constrain the maximum fraction of the ionizing power that can be generated by a hidden AGN. We correlate this fraction with classical indicators of AGN photo-ionization: X-ray luminosity and nebular excitation, but find no significant correlations. Thus, while there is a strong contribution of starbursts to the excitation of the nuclear nebular emission in low-luminosity Seyferts, the contribution of the hidden AGN remains ...

Concepts
Powered ByUnsilo

Stellar Velocity Dispersions
Seyfert 2 Galaxies
Velocity Dispersions
Emission-line Spectra
Emission Line
Low-luminosity Seyferts
Emission Line Luminosity
Nebular Excitation
Hidden AGN
Stellar Populations

Introducing Weekly Round-ups!Beta

Powered by R DiscoveryR Discovery

Round-ups are the summaries of handpicked papers around trending topics published every week. These would enable you to scan through a collection of papers and decide if the paper is relevant to you before actually investing time into reading it.

Climate change Research Articles published between May 09, 2022 to May 15, 2022

R DiscoveryMay 16, 2022
R DiscoveryArticles Included:  2

Introduction: Climate change is a pervasive threat to global biodiversity and is expected to have profound effects on the resilience and abundance of ...

Read More

Climate change Research Articles published between May 02, 2022 to May 08, 2022

R DiscoveryMay 09, 2022
R DiscoveryArticles Included:  2

We studied the fungal DNA present in a lake sediment core obtained from Trinity Peninsula, Hope Bay, north-eastern Antarctic Peninsula, using metabarc...

Read More

Climate change Research Articles published between Apr 25, 2022 to May 01, 2022

R DiscoveryMay 02, 2022
R DiscoveryArticles Included:  5

Introduction: Climate change and flooding events in South Ontario Climate change is altering climate patterns and adding pressure to climate systems a...

Read More

Climate change Research Articles published between Apr 18, 2022 to Apr 24, 2022

R DiscoveryApr 25, 2022
R DiscoveryArticles Included:  5

Introduction: Climate change triggers stark effects on species geographic ranges, leading to range shifts and disruptions in the functioning of ecosys...

Read More

Good health Research Articles published between Apr 18, 2022 to Apr 24, 2022

R DiscoveryApr 25, 2022
R DiscoveryArticles Included:  4

This study reviews the contributions made by each article in the theme issue with reference to case study examples of contemporary corporate social re...

Read More

Coronavirus Pandemic

You can also read COVID related content on R COVID-19

R ProductsCOVID-19

ONE PROBLEM . ONE PURPOSE . ONE PLACE

Creating the world’s largest AI-driven & human-curated collection of research, news, expert recommendations and educational resources on COVID-19

COVID-19 Dashboard