Abstract
THE high energy X-ray source, Cygnus XR-1, exhibits a variable intensity between states which differ in flux at lower energies (typically 3 to 6 keV) by a factor of three (refs 1–5). Although the transitions between these ‘high’ and ‘low’ flux states occur at irregular intervals, the transition itself usually takes no more than one day in either direction. We report here an observation of such a transition at energies above 20 keV which shows that the spectrum of Cyg XR-1 exhibits the pivoting effect during intensity transitions expected from two-temperature accretion disk models of the X-ray emitting region6,7.
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References
Holt, S. S., Kaluzienski, L. J., Boldt, E. A. & Serlemitsos, P. J., Nature 261, 213 (1976).
Tananbaum, H., Gursky, H., Kellogg, E., Giacconi, R. & Jones, C., Astrophys. J. 177, L5 (1972).
Kaluzienski, L. J., Holt, S. S., Boldt, E. A. & Serlemitsos, P. J. IAU Circ. No. 2863 (1975).
Walker, E. N., Brownlie, G. D., Mason, K. O., Sanford, P. W. & Quintanilla, A. R., Nature 263, 393 (1976).
Sanford, P. W., Ives, J. C., Bell Burnell, S. J., Mason, K. O. & Murdin, P., Nature 256, 109 (1975).
Shapiro, S. L., Lightman, A. P. & Eardley, D. M., Astrophys. J. 204, 187 (1976).
Eardley, D. M. & Lightman, A. P., Nature 262, 196 (1976).
Dennis, B. R., Frost, K. J., Lencho, R. J. & Orwig, L. E., Space Sci. Instr. (in the press).
Dolan, J. F., Crannell, C. J., Dennis, B. R., Orwig, L. E., Maurer, G. S. & Frost, K. J., Astrophys. (in the press).
Bolton, C. T., Astrophys. J. 200, 269 (1975).
Dolan, J. F., Dennis, B. R., Crannell, C. J., Frost, K. J. & Orwig, L. E., Highlights of Astronomy 4 (in the press).
Boldt, E., X-Ray Binaries NASA SP-389, 369 (1976).
Coe, M. J., Engel, A. R. & Quenby, J. J., Nature 259, 544 (1976).
Lampton, M., Margon, B. & Bowyer, S., Astrophys. J. 208, 177 (1976).
Alme, M. L. & Wilson, J. R., Astrophys. J. 210, 233 (1976).
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DOLAN, J., CRANNELL, C., DENNIS, B. et al. Intensity transitions in Cyg XR-1 observed at high energies from OSO 8. Nature 267, 813–815 (1977). https://doi.org/10.1038/267813a0
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DOI: https://doi.org/10.1038/267813a0
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