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X-Ray and Optical Observations of Quasars

Published online by Cambridge University Press:  14 August 2015

Harvey Tananbaum  and
Herman L. Marshall
Harvey Tananbaum
Affiliation:
Harvard-Smithsonian Center for Astrophysics
Herman L. Marshall
Affiliation:
Harvard-Smithsonian Center for Astrophysics

Extract

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The first Einstein observations established that quasars, as a class, are luminous X-ray emitters (Tananbaum et al. 1979). Since then, one of our major programs has been to carry out further X-ray and optical observations to improve our estimate of the contribution of quasars to the 2 keV extragalactic isotropic X-ray background and also to reconcile number counts of discrete X-ray sources with reported optical number counts of quasars (cf. Zamorani et al. 1981 and references therein). This paper is a preliminary report on our observations of the 1.7 square degree field studied originally by Braccesi and his colleagues (Formiggini et al. 1980 and Braccesi et al. 1980). A more detailed presentation of our results is in preparation (Marshall et al., 1981).

Type
Research Article
Information
Symposium - International Astronomical Union , Volume 97: Extragalactic Radio Sources , 1982 , pp. 269 - 277
Copyright
Copyright © Reidel 1982 

References

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