H2 emission from type 1 Seyferts and quasars - Molecular tori around bare nuclei
- National Astronomical Observatory, Mitaka (Japan) Kyoto Univ. (Japan) Observatorio Interamericano de Cerro Tololo, La Serena (Chile) Royal Observatory, Edinburgh (Scotland)
Results are presented from a search for H2 emission lines in the near-IR for a group of 18 type 1 Seyferts and quasars. Lines were detected in 12 objects including two quasars, 3C 273 and IRAS 13349 + 2438 and one bare type 1 Seyfert NGC 3783. The data for H2 and Br-gamma lines are analyzed and the H2 emission properties are compared with those in dusty AGN and H II region galaxies. The results suggest that H2 emission is closely related to AGN activity and that X-ray heating is the mechanism for H2 excitation in type 1 Seyferts and quasars. A transition from type 2 Seyferts to type 1 Seyferts is proposed in terms of the consumption of molecular clouds due to mass inflow to the center and star-forming regions. It is shown that the observations, combined with other observations from X-ray to radio wavelengths, may be explained consistently with the molecular torus models. 94 refs.
- OSTI ID:
- 6865067
- Journal Information:
- Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 352; ISSN ASJOA; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
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640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC GASES
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
ELEMENTS
EMISSION SPECTRA
FLUIDS
GALAXIES
GALAXY NUCLEI
GASES
HEATING
HYDROGEN
INFRARED RADIATION
INTERSTELLAR SPACE
IONIZING RADIATIONS
LINE WIDTHS
MATHEMATICAL MODELS
NEAR INFRARED RADIATION
NONMETALS
QUASARS
RADIATIONS
RADIOWAVE RADIATION
SEYFERT GALAXIES
SPACE
SPECTRA
X RADIATION