The thin layer of Warm Ionized Gas: towards a 3-D reconstruction of the   spatial distribution of HII regions
  HII regions are known to contribute to the so-called thin layer of the diffuse Warm Ionized Gas. In order to constrain this contribution, we reconstruct the 3-D distribution of the sources. A detailed spatial analysis of the largest up-to-date sample of HII regions is presented. 
Roberta Paladini, Rod Davies, Gianfranco DeZotti