Abstract The results of the initial stage of the CfA survey of Quasar Energy Distributions (QEDs) are reviewed. Einstein Imaging Proportional Counter (IPC) spectra of 33 quasars have been studied by fitting a single power law slope and absorption by an equivalent column density of neutral hydrodgen, N H. A wide range of energy index, α E, is seen and α E increases as the radio loudness of a quasar decreases. Comparison with the higher energy HEAO-A2 data leads us to a two-component model for th x-ray spectrum. The x-ray column density is systematically lower than the 21 cm measured Galactic column density along the same line of sight. This discrepancy is not present in a comparison sample of Bl Lac objects and so the cause must be intrinsic to the quasar. A third component, an ultra-soft excess (<0.28keV) above a single power law in the quasar spectra, provides a plausible explanation. This excess could be the high energy tail of the blue bump in the optical and ultra-violet (UV).


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Einstein spectra of quasars


    Contributors:

    Published in:

    Publication date :

    1988-01-01


    Size :

    9 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Einstein spectra of quasars

    Wilkes, Belinda J. | NTRS | 1988



    Medium resolution near-infrared spectra of the host galaxies of nearby quasars

    Le, Huynh Anh Nguyen / Pak, Soojong / Im, Myungshin et al. | Elsevier | 2014


    Veel ophef rond 'naakte quasars'

    Online Contents | 1995


    The First Stars and Quasars

    Loeb, A. / European Space Agency | British Library Conference Proceedings | 1998