Published online by Cambridge University Press: 12 April 2016
We discuss the link between the halo plasma temperature and the power-law spectral index of the extragalactic background radiation. This link is of strong influence for the derivation of the Galactic halo intensity distribution. In principal, we can distinguish between two combinations of Galactic halo plasma temperature and power-law slope. The first combination consists of a halo plasma of T halo = 106 K and an E −2 approximation of the extragalactic background radiation. The second combination is T halo = 106.2 K and an E −1.5. Both combinations are in agreement with recent observational results, thus it is not feasible to discriminate between both models on the basis of X-ray data available. But, the soft X-ray background intensity distribution in the ¼ keV and ¾ keV ROSAT energy bands differs significantly. The T halo = 106 K and an E −2 allows a patchy ¼ keV intensity distribution while the T halo = 106.2 K and an E −1.5 predicts a much smoother intensity variation since the hotter halo plasma accounts for a significant fraction of the ¾ keV background radiation.