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Spectral Properties of Blazars Observed at Ultraviolet and X-Ray Frequencies

  • A. Treves
  • G. Ghisellini
  • L. Maraschi
  • E. G. Tanzi
Chapter
Part of the Astrophysics and Space Science Library book series (ASSL, volume 121)

Abstract

The large majority of all Blazars observed in the far ultraviolet (26 objects) are considered. Broad band spectral data are collected choosing measurements close in time and corrected for contamination from the surrounding galaxy. It is found that the overall spectrum of this class of objects steepens substantially between radio and infrared and between infrared and ultraviolet frequencies but not between ultraviolet and X-ray frequencies. The spectral slopes in different bands are correlated from X-ray to IR frequencies. The 6 X-ray selected objects contained in the sample show spectra which are flatter than average in all bands. The average X-ray luminosity of the whole sample and that of the X-ray selected group are the same. It is suggested that relativistic beaming may enhance the radio but not the X-ray emission of radio selected blazars.

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Copyright information

© Springer Science+Business Media Dordrecht 1986

Authors and Affiliations

  • A. Treves
    • 1
  • G. Ghisellini
    • 2
  • L. Maraschi
    • 1
  • E. G. Tanzi
    • 3
  1. 1.Dipartimento di FisicaUniversità di MilanoItaly
  2. 2.International School for Advanced StudiesTriesteItaly
  3. 3.Istituto di Fisica Cosmica CNRMilanoItaly

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