The problem of extinction and thermal reradiation by dust in active galactic nuclei and quasi-stellar objects

Journal Article · Tue Aug 01 00:00:00 EDT 1989 · Publications of the Astronomical Society of the Pacific; (USA)

DOI:https://doi.org/10.1086/132490· OSTI ID:5356585

Congdon, C; Stein, W A ^[1]

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1. Minnesota Univ., Minneapolis (USA)

Published H-alpha/H-beta ratios and infrared-to-visual flux ratios are examined as potential diagnostics for dust in Seyfert I galaxies, Seyfert 2 galaxies, and QSOs. H-alpha/H-beta ratio distributions are very broad although some subtle distinctions may be evident among the various classes of objects. The distributions of the ratio of about 10-micron luminosity to that at visual-ultraviolet wavelengths are more narrow, and clear distinctions are evident among the various types of object. Clearly both H-alpha/H-beta and infrared emission together help determine the obscuring effects of dust. More homogeneous data are desirable but will require considerably large telescope observing time in order to pursue these results further. 35 refs.

• OSTI ID: 5356585
• Journal Information: Publications of the Astronomical Society of the Pacific; (USA), Vol. 101; ISSN 0004-6280
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALAXY NUCLEI
COSMIC DUST
QUASARS
SEYFERT GALAXIES
BALMER LINES
INFRARED RADIATION
INTERSTELLAR SPACE
LUMINOSITY
RADIATION FLUX
VISIBLE RADIATION
COSMIC RADIO SOURCES
DUSTS
ELECTROMAGNETIC RADIATION
GALAXIES
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
RADIATIONS
SPACE
640105* - Astrophysics & Cosmology- Galaxies
640102 - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources