X ray measurements taken with the HEAO-1 and -2 satellites are examined for clues to the source of emissions from active galactic nuclei (AGN). The data covered the energy range 2-100 keV and 0.5-4.5 keV and encompassed quasars, BL Lac objects, Seyfert I galaxies and broadline radio galaxies. The broadline spectra were best fit with a power law with a slope of about 0.68. The continua displayed roughly equivalent energy at all wavelengths except for radio bands. Spectral variability was detected in the BL Lac objects, which may emit optical, UV and soft X ray radiation from optically thin synchrotron emission with a hard X ray tail from inverse Compton scattering. No strong variability was evidenced with other AGN, suggesting that the emitting regions are below the Eddington luminosity and thus exhibit stable flow characteristics.
X-ray spectra and time variability of active galactic nuclei
Advances in Space Research ; 3 , 10-12
1984-01-01
Miscellaneous
No indication
English
X-ray variability of active galactic nuclei and the flare model
Online Contents | 2006
|X-ray variability of active galactic nuclei and the flare model
Elsevier | 2005
|Multiwavelength Monitoring of Active Galactic Nuclei
British Library Conference Proceedings | 1993
|ROSAT: Observations of active galactic nuclei
British Library Online Contents | 1992
|