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		| Paper: | 
		Tiny-Scale Atomic Structure and the Cold Neutral Medium—Review and Recap | 
	 
	
		| Volume: | 
		365, SINS — Small Ionized and Neutral Structures in the Diffuse Interstellar Medium | 
	 
	
		| Page: | 
		3 | 
	 
	
		| Authors: | 
		Heiles, C. | 
	 
	
	
		| Abstract: | 
		Almost a decade ago I wrote an article with the same title as this. It focused on the physical properties of the Tiny-Scale Atomic Structure (TSAS) as discrete structures of the Cold Neutral Medium (CNM). To be observable, tiny discrete structures that don’t grossly violate pressure equilibrium need two attributes: low temperatures and geometrical anisotropy. Here I update that article. I discuss thermal and pressure equilibrium, ionization, optical lines, H2 abundance, and evaporation. | 
	 
	
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