The 'semitorrid' gas observed in the direction of Gamma-2 Velorum and the Gum nebula

On the basis of recent IUE observations in the far-ultraviolet, the authors report the detection of a 'semitorrid' region of the interstellar medium in the direction of Gamma-2 Velorum and the Gum nebula. The characteristic temperature of this gas is in the 40,000 K range, between the warm (around 1000 K) and hot (roughly 100,000-1,000,000 K) regions reported by various investigators. This temperature is compatible with the theoretical temperature ascribed to the 'fossil Stromgren sphere' by Brandt et al. and Alexander et al.