Abstract
We have used the twin 11-m diameter mirrors of the NASA Jet Propulsion Laboratory's solar energy facility to observe high-energy γ rays from Cyg X-3 using the atmospheric Cerenkov technique. Observations of photons with energies above 1012 eV modulated with the 4.8 h period of the X-ray source have been reported previously by the Crimean Astrophysical Observatory1–6 and the Fred Whipple Observatory7,8. We report here data from ∼105 air shower events obtained 29 August–6 September 1981 with an approximate threshold energy of 500 GeV. A positive signal with an amplitude of 10.9±2.5% of the background cosmic ray rate appears near phase 0.6 of the 4.8-h cycle, in which phase 0.0 corresponds to minimum X-ray emission. This observation, together with previous Cerenkov detections, indicates that the high energy emission from Cyg X-3 is evolving on a time scale of a few years which suggests a recent origin for the system in its present form.
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References
Vladimirsky, B. M., Stepanian, A. A. & Fomin, V. P. Proc. 13th int. Conf. Cosmic Rays 1, 456–460 (1973).
Vladimirksy, B. M., Neshpor, Yu. I., Stepanian, A. A. & Fomin, V. P. Proc. 14th int. Conf. Cosmic Rays 1, 118–122 (1975).
Stepanian, A. A., Vladimirsky, B. M., Neshpor, Yu. I. & Fomin, V. P. Proc. 15th int. Conf. Cosmic Rays 1, 135–140 (1977).
Neshpor, Yu. I. et al. Astrophys. Space Sci. 61, 349–355 (1979).
Mukanov, J. B., Nesterova, N. M., Stepanian, A. A. & Fomin, V. P. Proc. 16th int. Conf. Cosmic Rays 1, 143–146 (1979).
Neshpor, Yu. I., Zyskin, Yu. L., Mukanov, J. B., Stepanian, A. A. & Fomin, V. P. Phil. Trans. R. Soc. A301, 633–634 (1981).
Danaher, S., Fegan, D. J., Porter, N. A. & Weekes, T. C. Nature 289, 568–569 (1981).
Weekes, T. C., Danaher, S., Fegan, D. J. & Porter, N. A. Astr. Astrophys. Lett. 104, L4–L6 (1981).
van der Klis, M. & Bonnet-Bidaud, J. M. Astr. Astrophys. Lett. 95, L5–L7 (1981).
Lamb, R. C., Fichtel, C. E., Hartman, R. C., Kniffen, D. A. & Thompson, D. J. Astrophys. J. Lett. 212, L63–L66 (1977).
Bennett, K. et al. Astr. Astrophys. 59, 273–274 (1977).
Bignami, C. F., Maraschi, L. & Treves, A. Astr. Astrophys. 55, 155–158 (1977).
Milgrom, M. & Pines, D. Astrophys. J. 220, 272–278 (1978).
Thompson, D. J., Fichtel, C. E., Hartman, R. C., Kniffen, D. A. & Lamb, R. C. Astrophys. J. 213, 252–262 (1977).
Kanbach, G. et al. Astr. Atrophys. 90, 163–169 (1980).
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Lamb, R., Godfrey, C., Wheaton, W. et al. Cygnus X-3 observed at photon energies above 500 GeV. Nature 296, 543–544 (1982). https://doi.org/10.1038/296543a0
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DOI: https://doi.org/10.1038/296543a0
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