A Scenario for the Ionization of the Diffuse ISM in Galaxies and the IGM in Clusters

摘要: The diffuse Hα emitted from the discs of spirals is order 50% their total emission (Ferguson et al., 1996; Zurita 2000), requiring strong energy input. Energy stellar winds or SNe falls short by two orders magnitude, white dwarf Lyc one order. Sciama’s (e.g. 1990) decaying neutrino theory offers an explanation, but clear evidence against it exists (Bowyer 1999). OB stars are probable candidates, embedded in H II regions which absorb flux; any escaping flux must travel up to kpc I ionize gas (DIG). We have that a major fraction escapes, and modelled its propagation through DIG.