P. Ubertini, A. Bazzano, C. D. La Padula and V. F. Polcaro, Laboratono di Astrofisica Spaziale, Frascati; and R. K. Manchanda, Tata Institute of Fundamental Research, Bombay, communicate: "We report the discovery of a line feature between 64 and 76 keV in the spectrum of the Crab. Observations in the hard x-ray range were made with a high-pressure Xe-multiwire proportional counter during a trans-Mediterranean balloon flight on 1979 Aug. 26. Results are consistent with a line intensity of ~ 2 x 10**-3 ph cm**-2 s**-1 and a line width of ~ 5 keV. The pulsed fraction of the source is ~ 20 percent of the total integrated emission in the range 20-130 keV."
International Astronomical Union Circular
- Pub Date:
- February 1980