Three cosmic x-ray sources have been observed from a water-launched rocket carrying two x-ray detectors to an altitude of 200 kilometers. The x-ray spectra, measured in the photon energy range between I and 40 kiloelectron volts, are all different. The sources in order of hardness of spectra are Cyg XR-1, Tau XR-1, and Sco XR-1. The intensity of Sco XR-J decreased at low photon energies. The differences in spectra might source mechanisms.
Measurements have been made from latitudes 22°N and 17°N with rocket‐borne, thin‐window proportional counters of a variable flux of low‐energy particles (electron energy greater than 3 kev) approaching the earth from the southern half of the sky. These particles were detected on three separate rocket flights at altitudes above 120 km and at an L value of approximately 1.1. The three measurements differ in intensity but are very similar in spectral shape, with approximately an E−1 dependence. A typical flux value is 100 particles/cm² kev sec ster at an energy of 4 kev. These particles are of particular importance in low‐energy X‐ray astronomy experiments where they may be the dominant source of background in certain regions of the sky.
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