Abstract
To form the Hubble diagram for quasi-stellar objects (QSOs),we have made use of the recently published data on X-ray fluxes of 159 QSOs observed from the Einstein Observatory. The scatter in the Hubble diagram and the lack of an obvious redshift-flux density correlation for these QSOs have been attributed to the observational selection effect that the intrinsically less luminous QSOs can be detected only in the nearby region of space. When the optical, radio and X-ray selection effects are removed, keeping only the intrinsically brighter sources, we obtain a sample of 16 QSOs having a small dispersion in X-ray luminosities (〈 logL x〉) = 46.12 ± 0.28), a statistically significant linear correlation between (logf x, logcz) pairs and a slopeA =-1.906 ± 0.061 of the linear regression oflog f x on logcz. This slope is consistent, at a confidence level of 95 per cent or greater, with the slope of-2.0 expected theoretically based on the assumption that the redshifts of QSOs are cosmological in nature.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bahcall, J. N., Turner, E. L. 1977, inIAU Symp. 74:Radio Astronomy and Cosmology, Ed. D. L. Jauncey, D. Reidel, Dordrecht, p. 295.
Burbidge, G. R., O’Dell, S. L. 1973,Astrophys. J. 183, 759.
Chanan, G. A., Margon, B., Downes, R. A. 1981,Astrophys. J. 243, L5.
Grindlay, J. E., Streiner, J. E., Forman, W. R., Canizares, C. R., McClintock, J. E. 1980,Astrophys J.,239, L43.
Henriksen, M. J., Marshall, F. E., Mushotzky, R. F. 1984,Astrophys J.,284, 491.
Hewitt, A., Burbidge, G. 1980,Astrophys. J. Suppl. Ser.,43, 57.
Kembhavi, A. K., Kulkarni, V. K. 1977,Mon. Not. R. astr. Soc.,181, 19P.
Ku, W. H. M., Helfand, D. J., Lucy, L. B. 1980,Nature,288, 323.
Lang, K. R., Lord, S. D., Johanson, J. M., Savage, P. D. 1975,Astrophys. J.,202, 583.
McCrea, W. H. 1972, inIAU Symp. 44:External Galaxies and Quasi-Stellar objects, Ed. D. S. Evans, D. Reidel, Dordrecht, p. 283.
Netzer, H., Yahil, A., Yaniv, R. 1978,Mon. Not. R. astr. Soc.,184, 21P.
Pica, A. J., Smith, A. G. 1983,Astrophys. J.,272, 11.
Reichert, G. A., Mason, K. O., Thorstensen, J. R., Bowyer, S. 1982,Astrophys. J.,260, 437.
Sandage, A. 1965,Astrophys. J.,141, 1560.
Sandage, A. 1967,Astrophys. J.,150, L9.
Schmidt, M. 1968,Astrophys. J.,151, 393.
Setti, G., Woltjer, L. 1973,Astrophys. J.,181, L61.
Setti, G., Zamorani, G. 1978,Astr. Astrophys.,66, 249.
Thakur, R. K., Sapre, A. K. 1978,Astrophys. Space Sci.,57, 119.
Tananbaum, H., Avni, Y., Branduardi, G., Elvis, M., Fabbiano, G., Feigelson, E., Giacconi, R., Henry, J. P., Pye, J. P., Soltan, A., Zamorani, G. 1979,Astrophys. J.,234, L9.
Usher, P. D. 1975,Astrophys. J.,198, L57.
Usher, P. D. 1978,Astrophys. J.,222, 40.
Zamorani, G., Giommi, P., Maccacaro, T., Tananbaum, H. 1984,Astrophys. J.,278, 28.
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., Condon, J. J., 1981,Astrophys J.,245, 357.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sapre, A.K., Mishra, V.D. An X-ray hubble diagram for quasi-stellar objects. Astrophys Astron 6, 49–56 (1985). https://doi.org/10.1007/BF02719528
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02719528