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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

Avni, Y., Soltan, A., Tananbaum, H., and Zamorani, G. 1980, Ap. J., 238, 800.Google Scholar
Bonoli, F., Braccesi, A., Marano, B., Merighi, R., and Zitelli, V. 1980, Astron. Astrophys., 90, L10.Google Scholar
Braccesi, A., Formiggini, L., and Gandolfi, E. 1970, Astron. Astrophys., 5, 264.Google Scholar
Braccesi, A., Zitelli, V., Bonoli, F., and Formiggini, L. 1980, Astron. Astrophys., 85, 80.Google Scholar
Cavaliere, A., Danese, L., DeZotti, G., and Franceschini, A. 1980 preprint.Google Scholar
Formiggini, L., Zitelli, V., Bonoli, F., and Braccesi, A. 1980, Astron. Astrophys. Suppl., 39, 129.Google Scholar
Green, R.F. and Schmidt, M. 1978, Ap.J.(Lett.), 220, L1.Google Scholar
Green, R.F. and Schmidt, M. 1981, private communication.Google Scholar
Kron, R.G. 1980, in Two Dimensional Photometry (ESO Workshop) Lindblad, P. O. and van der Laan, H., eds., Geneva, p.349.Google Scholar
Kron, R.G. and Chiu, L.T.G. 1981, preprint.Google Scholar
Kron, R.G. 1981, private communication.Google Scholar
Marshall, H.L., et al. 1981, in preparation.Google Scholar
Setti, G. and Woltjer, L. 1979, Astr. and Astrophys., 76, L1.Google Scholar
Tananbaum, H., Avni, Y., Branduardi, G., Elvis, M., Fabbiano, G., Feigelson, E., Giacconi, R., Henry, J.P., Pye, J.P., Soltan, A., and Zamorani, G. 1979, Ap.J. (Lett.), 234, L9.Google Scholar
Veron, P. and Veron, M.P. 1981, Astron. Astrophys., submitted.Google Scholar
Zamorani, G., Henry, J.P., Maccacaro, T., Tananbaum, H., Soltan, A., Avni, Y., Liebert, J., Stocke, J., Strittmatter, P.A., Weymann, R.J., Smith, M.G., and Condon, J.J. 1981, Ap. J., 245, 357.Google Scholar
Zamorani, G. 1981, private communication.Google Scholar