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Extragalactic X-Ray Sources and Their Contribution to the Diffuse Background: Invited Paper

Published online by Cambridge University Press:  14 August 2015

G. Setti  and
L. Woltjer
G. Setti
Affiliation:
Laboratorio di Radioastronomia CNR, University of Bologna, Italy
L. Woltjer
Affiliation:
Dept. of Astronomy, Columbia University, New York, N.Y., U.S.A.

Abstract

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We present estimates of the integrated contribution of extragalactic sources to the diffuse X-ray background in the 2–10 keV energy interval. It appears that classes of objects already detected as X-ray sources easily account for at least 10% of the background. Quasistellar objects, and possibly Seyfert and radio galaxies might contribute a larger fraction of the background intensity.

We also suggest that several of the unidentified X-ray sources in the UHURU catalogue at high galactic latitudes may be bright QSO's as yet unknown. The detection of a larger number of QSO's in the X-ray band may allow a decisive test for the cosmological interpretation of the redshifts of QSO's.

Type
Part III: Extragalactic Sources
Information
Symposium - International Astronomical Union , Volume 55: X- and Gamma-Ray Astronomy , 1973 , pp. 208 - 211
Copyright
Copyright © Reidel 1973 

References

Apparao, M.: 1968, Nature 219, 145.Google Scholar
Cavallo, G. and Messina, A.: 1972, Astrophys. Letters 10, 61.Google Scholar
Giacconi, R., Gursky, H., Kellogg, E. M., Murray, S., Schreier, E., and Tananbaum, H.: 1972, ‘The UHURU Catalogue of X-Ray Sources, Submitted to Astrophys. J. CrossRefGoogle Scholar
Gorenstein, P., Kellogg, E. M., and Gursky, H.: 1969, Astrophys. J. 156, 315.Google Scholar
Gursky, H., Kellogg, E. M., Leong, O., Tananbaum, H., and Giacconi, R.: 1971, Astrophys. J. 165, L43.Google Scholar
Gursky, H. Solinger, A., Kellogg, E. M., Murray, S., Tananbaum, H., Giacconi, R., and Cavaliere, A.: 1972, ‘X-Ray Emission from Rich Clusters of Galaxies’, submitted to Astrophys. J. Letters. Google Scholar
Rees, M. J. and Setti, G.: 1968, Nature 219, 127.Google Scholar
Schmidt, M.: 1971, in ‘Semaine d'étude sur les noyaux des galaxies’ Pontificiae Academiae Scientiarum Scripta Varia, No. 35, p. 387.Google Scholar
Setti, G. and Rees, M. J.: 1970, in Gratton, L. (ed.), ‘Non-Solar X- and Gamma-Ray Astronomy’, IAU Symp. 37, 352.Google Scholar
Setti, G. and Woltjer, L.: 1970a, Astrophys: Space Sci. 9, 185.Google Scholar
Setti, G. and Woltjer, L.: 1970b, Nature 227, 586.Google Scholar
Silk, J.: 1968, Astrophys. J. 151, L19.CrossRefGoogle Scholar
Silk, J.: 1969, Nature 221, 347.Google Scholar
Tucker, W. H.: 1970, Astrophys. J. 161, 1161.Google Scholar