|   | 
				
					
	
		  | 
	 
	
		| Paper: | 
		Hydrogen Column Density Measurements toward White Dwarfs for D/H Studies | 
	 
	
		| Volume: | 
		348, Astrophysics in the Far Ultraviolet: Five Years of Discovery with FUSE | 
	 
	
		| Page: | 
		460 | 
	 
	
		| Authors: | 
		Vennes, S.; Chayer, P.; Dupuis, J.; Moos, H.W.; Lanz, T. | 
	 
	
	
		| Abstract: | 
		Hot white dwarfs provide sources of extreme ultraviolet (EUV) radiation against which the photoionization continua of interstellar H I, He I, and He II are measured. The column density measurements depend on a detailed knowledge of the intrinsic EUV luminosity of the sources. We discuss recent progress in the study of low- and high-metallicity white dwarfs enabling a study of interstellar hydrogen and helium continuum absorptions toward many lines of sight. We compare the EUV-based measurements to recent hydrogen column density measurements based on Lyα line profiles and discuss the implications for D/H and O/H ratios in the local interstellar medium. | 
	 
	
		| 
			
			
		 | 
	 
	
		  | 
	 
 
					 
				 | 
				  |