Broad-line region of active galactic nuclei revisited

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Publ. Astron. Soc. Pac.; (United States)

DOI:https://doi.org/10.1086/132270· OSTI ID:6391800

Collin-Souffrin, S; Lasota, J P

Broad emission lines which are the most characteristic features of active galactic nuclei and quasars can be separated into two distinct systems: the high-ionization lines (HIL) and low-ionization lines (LIL). HILs are emitted by low-pressure optically-thin clouds illuminated by a rather soft continuum radiation. LILs are produced by a high-pressure optically-thick medium, illuminated mainly by hard X-rays, possibly the outer region of an accretion disk. This version of the photoionization model of the broad-line region is still unable to provide a consistent explanation of the unusual intensities of the iron Fe II lines in strong optical Fe II emitters. 54 references.

• Research Organization: CNRS, Institut d'Astrophysique, Paris (France); Paris Observatoire, Meudon (France)
• OSTI ID: 6391800
• Journal Information: Publ. Astron. Soc. Pac.; (United States), Journal Name: Publ. Astron. Soc. Pac.; (United States) Vol. 100; ISSN PASPA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCRETION DISKS
CHARGED PARTICLES
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION SPECTRA
GALAXY NUCLEI
HARD X RADIATION
IONIZATION
IONIZING RADIATIONS
IONS
IRON
IRON IONS
MATHEMATICAL MODELS
METALS
PHOTOIONIZATION
QUASARS
RADIATIONS
SPECTRA
TRANSITION ELEMENTS
X RADIATION