Differential line development and the complex structure of the broad-line region in Fairall 9

Journal Article · Fri Jun 01 04:00:00 EDT 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168853· OSTI ID:6696753

Zheng, Wei; O'Brien, P T ^[1]

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1. University College, London (England)

It is found that the profiles of the UV emission lines Ly-alpha, C IV 1549, and Mg II 2798 in the Seyfert 1 galaxy Fairall 9 vary such that the lines are broader when the object is brighter. The profile changes occur mainly near the line center for Ly-alpha and C IV and in the wings for Mg II. These results indicate that the broad-line region (BLR) has a complex structure, possibly with nonspherical components. It is derived that part of the Ly-alpha and practically all of the C IV emission comes from optically thin clouds in the inner region of the BLR which are heated by an anisotropic UV continuum. These clouds may be moving radially. The Mg II and the rest of the Ly-alpha emission comes from very optically thick clouds which are more spherically distributed at a larger radius and heated mainly by X-ray radiation. 34 refs.

• OSTI ID: 6696753
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 356; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METALS
COSMIC GASES
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION SPECTRA
FLUIDS
GALAXIES
GASES
HEATING
IONIZING RADIATIONS
LINE WIDTHS
LYMAN LINES
MAGNESIUM
METALS
RADIATIONS
SEYFERT GALAXIES
SPATIAL DISTRIBUTION
SPECTRA
ULTRAVIOLET SPECTRA
VARIATIONS
X RADIATION