Sign on

SAO/NASA ADS Astronomy Abstract Service


· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· On-line Data
· References in the article
· Citations to the Article (190) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (1)
· NED Objects (1)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Hot dust on the outskirts of the broad-line region in Fairall 9
Authors:
Clavel, J.; Wamsteker, W.; Glass, I. S.
Affiliation:
AA(International Ultraviolet Explorer Observatory, Madrid, Spain), AB(International Ultraviolet Explorer Observatory, Madrid, Spain), AC(South African Astronomical Observatory, Observatory, Republic of South Africa)
Publication:
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 337, Feb. 1, 1989, p. 236-250. (ApJ Homepage)
Publication Date:
02/1989
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
Active Galactic Nuclei, Cosmic Dust, Infrared Sources (Astronomy), Seyfert Galaxies, Spectral Energy Distribution, Ultraviolet Spectra, Continuous Spectra, Light Curve, Line Spectra, Near Infrared Radiation
DOI:
10.1086/167100
Bibliographic Code:
1989ApJ...337..236C

Abstract

The Seyfert galaxy Fairall 9 (F9) has been observed in the far-UV and optical range with the IUE, and at 27 different epochs at J, H, K, and L. The UV continuum underwent dramatic variations, its intensity decreasing by a factor 33 from a maximum in 1978 to a deep minimum in mid-1984. The near-IR and optical fluxes changed by a factor of about three and in the same sense as the UV. The K and L emission are interpreted as thermal radiation from dust lying at about 1 lt-yr from the UV source. The Ly-alpha 1216, C IV 1550, and Mg II 2800 emission-line intensities also vary in the same sense as the UV continuum but with a lag of 155 + or - 45 days. This strongly suggests that the broad-line region (BLR) gas is photoionized and lies inside the dust shell. Strong evidence is presented that the Mg II 2800 line emissivity depends primarily on the density of soft X-ray photons, as postulated in optically thick photoionization models of the BLR.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences



More Article Retrieval Options

HELP for Article Retrieval


Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

  New!

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