Abstract
OBSERVATIONS of electromagnetic radiation from the Crab have been made to at least 1 GeV (ref. 1) and possibly as high as 1012 eV (refs 2 and 3). The Crab is unique among strong X-ray sources in that the major component in the low energy range (1–10 keV) shows little or no temporal variation. A small (≲ 10% at 10 keV) pulsed component from NP0532 is observed in the X-ray region, but its strength relative to the constant component increases with increasing X-ray energy. Gamma ray observations of the Crab in the 15–100 MeV range have yielded rather uncertain results with reported upper limits4,5 and fluxes6–10 in apparent or near conflict. As the reported intensities were just marginally detectable above atmospheric background with the balloon experiments which produced the observations, this seems understandable.
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References
McBreen, B., Ball, S. E., jun., Campbell, M., Greisen, K., and Koch, D., Astrophys. J., 184, 571–580 (1973).
Grindlay, J. E., Astrophys. J. Lett., 174, L9–L17 (1972).
Fazio, G. G., Hemken, H. F., O'Mongain, E., and Weekes, T. E., Astrophys. J. Lett., 175, L117–L122 (1972).
Frye, G. M., jun., and Wang, C. P., Astrophys. J., 158, 925–937 (1969).
Kettenring, G., Mayer-Hasselwander, H. A., Pfeffermann, E., Pinkau, K., Rothermel, H., and Sommer, M., Proc. 12th int. Cosmic Ray Conf., 1, 57–62 (1971).
Browning, R., Ramsden, D., and Wright, P. J., Nature, 232, 99–101 (1971).
Albats, P., Frye, G. M., jun., Zych, A. D., Mace, O. B., Hopper, V. D., and Thomas, J. A., Nature, 240, 221–224 (1972).
Kinzer, R. L., Share, G. H., and Seeman, N., Astrophys. J., 180, 547–549 (1973).
Parlier, B., et al., Nature phys. Sci., 242, 117–120 (1973).
Helmken, H., and Hoffman, J., Proc. 13th int. Cosmic Ray Conf., 1, 31–35 (1973).
Derdeyn, S. M., Erhmann, C. H., Fichtel, C. E., Kniffen, D. A., and Ross, R. W., Nucl. Instr. Meth., 98, 557–566 (1972).
Fichtel, C. E., Hartman, R. C., and Kniffen, D. A., Astrophys. J. Lett., 186, L99–L103 (1973).
Rankin, J. M., Counselmann, C. C., III, and Richards, D. W., Astr. J., 76, 686–690 (1971).
Fishman, G. J., Harnden, R. F., jun., and Haymes, R. C., Astrophys. J. Lett., 156, L17–L110 (1969).
Shklovsky, I. S., Astrophys. J., 159 (1970).
Thompson, D. J., Bignami, G. F., Fichtel, C. E., and Kniffen, D. A., Astrophys. J. Lett., 190, L51–L53 (1974).
Kurfess, J. D., Astrophys. J. Lett., 168, L39–L42 (1971).
Orwig, L. E., Chupp, E. L., and Forrest, D. J., Nature phys. Sci., 231, 171–172 (1971).
Laros, J. G., Matteson, J. L., and Pelling, R. M., Nature phys. Sci., 246, 109–111 (1973).
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KNIFFEN, D., HARTMAN, R., THOMPSON, D. et al. Gamma radiation from the Crab Nebula above 35 MeV. Nature 251, 397–399 (1974). https://doi.org/10.1038/251397a0
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DOI: https://doi.org/10.1038/251397a0
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