Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:0808.4121)
· References in the article
· Citations to the Article (2) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (7)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
On the anomalous silicate emission features of active galactic nuclei: a possible interpretation based on porous dust
Authors:
Li, M. P.; Shi, Q. J.; Li, Aigen
Affiliation:
AA(Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA), AB(Department of Science and Engineering of Shuda College, Hunan Normal University, Changsha, Hunan 410081, China), AC(Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211, USA)
Publication:
Monthly Notices of the Royal Astronomical Society: Letters, Volume 391, Issue 1, pp. L49-L53. (MNRAS Homepage)
Publication Date:
11/2008
Origin:
MNRAS
MNRAS Keywords:
galaxies: active, galaxies: ISM: dust, infrared: galaxies
DOI:
10.1111/j.1745-3933.2008.00553.x
Bibliographic Code:
2008MNRAS.391L..49L

Abstract

The recent Spitzer detections of the 9.7μm Si-O silicate emission in type 1 active galactic nuclei (AGN) provide support for the AGN unification scheme. The properties of the silicate dust are of key importance to understand the physical, chemical and evolutionary properties of the obscuring dusty torus around the AGN. Compared to that of the Galactic interstellar medium (ISM), the 10μm silicate emission profile of type 1 AGN is broadened and has a clear shift of peak position to longer wavelengths. In literature, this is generally interpreted as an indication of the deviations of the silicate composition, size and degree of crystallization of the AGN from that of the Galactic ISM. In this Letter, we show that the observed peak shift and profile broadening of the 9.7μm silicate emission feature can be explained in terms of porous composite dust consisting of ordinary interstellar amorphous silicate, amorphous carbon and vacuum. Porous dust is naturally expected in the dense circumnuclear region around the AGN, as a consequence of grain coagulation.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints