Continuum distributions of active galactic nuclei. [Radio, optical, infrared, and x-ray]

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5413050

Cruz-Gonzalez, I

This thesis describes a study of the broad band spectral energy distributions of a large sample of active galactic nuclei. The sample consists of 25 BL Lac objects, 92 quasars and 128 Seyfert galaxies. Observational data was compiled at radio, infrared, optical, and x-ray frequencies. The data set was complimented with infrared observations. Spectral indices, colors, and luminosities were derived and compared for each class of AGN. Different methods of analysis were applied to the broad band continuum data in order to understand the contribution to the observed continua of the various components (nonthermal source, galaxy starlight, and dust). The nonthermal mechanism is strongly favored to explain the infrared continua of most AGNs. No evidence for warm dust emission was found in BL Lac objects, quasars and Seyfert 1 galaxies. Only Seyfert 2 galaxies show a strong excess at 10 m which is interpreted as dust emission. The observed continua of BL Lac objects and quasars comes directly from the nonthermal source, while in Seyfert galaxies the central nonthermal source is considerably masked by the surrounding galaxy.

• Research Organization: Harvard Univ., Boston, MA (USA)
• OSTI ID: 5413050
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BL LACERTAE OBJECTS
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
GALAXIES
INFRARED SPECTRA
LUMINOSITY
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
QUASARS
RADIATIONS
RADIOWAVE RADIATION
SEYFERT GALAXIES
SPECTRA
VISIBLE SPECTRA
X-RAY SPECTRA