| | |
| | |
Stat |
Members: 3643 Articles: 2'488'730 Articles rated: 2609
29 March 2024 |
|
| | | |
|
Article overview
| |
|
AGN dust tori at low and high luminosities | Sebastian F. Hoenig
; Thomas Beckert
; | Date: |
2 Jul 2007 | Abstract: | A cornerstone of AGN unification schemes is the presence of an optically and
geometrically thick dust torus. It provides the obscuration to explain the
difference between type 1 and type 2 AGN. We investigate the influence of the
dust distribution on the Eddington limit of the torus. For smooth dust
distributions, the Eddingtion limit on the dust alone is 5 orders of magnitudes
below the limit for electron scattering in a fully ionized plasma, while a
clumpy dust torus has an Eddington limit slightly larger than the classical
one. We study the behaviour of a clumpy torus at low and high AGN luminosities.
For low luminosities of the order of ~10^42 erg/s, the torus changes its
characteristics and obscuration becomes insufficient. In the high luminosity
regime, the clumpy torus can show a behaviour which is consistent with the
"receding torus" picture. The derived luminosity-dependent fraction of
type-2-objects agrees with recent observational results. Moreover, the
luminosity-dependent covering factor in a clumpy torus may explain the presence
of broad-line AGN with high column densities in X-rays. | Source: | arXiv, arxiv.0707.0162 | Services: | Forum | Review | PDF | Favorites |
|
|
No review found.
Did you like this article?
Note: answers to reviews or questions about the article must be posted in the forum section.
Authors are not allowed to review their own article. They can use the forum section.
browser claudebot
|
| |
|
|
|
| News, job offers and information for researchers and scientists:
| |