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		| Paper: | 
		Neutral ISM in the Interacting Spiral NGC 4647 | 
	 
	
		| Volume: | 
		320, The Neutral ISM in Starburst Galaxies | 
	 
	
		| Page: | 
		156 | 
	 
	
		| Authors: | 
		Cullen, H.; Alexander, P.; Green, D.; Sheth, K. | 
	 
	
	
		| Abstract: | 
		NGC 4647 is an example of a late-type galaxy believed to be in the early stages of interaction with an early-type system. It appears to be both HI deficient and CO rich. Whilst the HI data indicate the system has a low atomic gas surface density, the 12CO (J = 2 → 1) flux gives a molecular gas mass of ∼ 6 × 109 MSolar corresponding to a surface density ∼ 20 MSolar  pc−2, significantly larger than average for a galaxy of this type. The large CO to HI surface density ratio could be explained by enhanced HI to H2 conversion in this system. | 
	 
	
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