Radiation from a Low-Density Plasma at 10⁶ ° - 10⁸ ° K

The emission from a hot, low-density plasma due to bremsstrahlung, radiative recombination, and electron collision-induced line emission is calculated. Results are given for the total energy emission rate as a function of temperature and also for the emission in the region 2-8 A, which is the principal region of sensitivity for the detectors in the recent X-ray rocket experiments. The emission spectrum from such an optically thin plasma at 10 K is given. This spectrum has a number of strong emission lines. If the observed cosmic X-ray sources are actually hot, low-density gases, as is believed by many, these lines should be detectable.