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Observations of AGN with the Extreme Ultraviolet Explorer

Published online by Cambridge University Press:  19 July 2016

Herman L. Marshall
Herman L. Marshall*
Affiliation:
Eureka Scientific, Inc. 2452 Delmer St, Suite 100 Oakland, CA 94602 Massachusetts Institute of Technology 70 Vasser St., 37-667a Cambridge, MA 02139

Abstract

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The first results from surveys performed in the extreme ultraviolet (EUV) will be described in the context of studies of active galaxies and BL Lac objects. About a dozen extra-galactic sources are known so far to emit sufficient EUV radiation that they are detectable even through the Galactic interstellar medium. These results are interpreted in the context of a model of EUV or soft X-ray excesses in the case of AGN. In the case of BL Lac objects, the detections indicate that the steep soft X-ray power law spectra continue into the EUV and that there is little intrinsic gas. Finally, there now exists EUV spectra from the Extreme Ultraviolet Explorer for one BL Lac, PKS 2155-304 and two AGN: Mk 478 and NGC 5548. The spectra show no significant spectral features; for AGN, it indicates that optically thin and emission line models may have a difficult time explaining the EUV and soft X-ray bumps.

Keywords

AGNBL Lac Objects
Type
New Observations of AGN with Specific Instruments
Information
Symposium - International Astronomical Union , Volume 159: Multi-Wavelength Continuum Emission of AGN , 1994 , pp. 105 - 110
Copyright
Copyright © Kluwer 1994 

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