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		| Paper: | 
		Massive Star Formation and Dust in Collisional Ring Galaxies: From GALEX to Spitzer | 
	 
	
		| Volume: | 
		381, The Second Annual Spitzer Science Center Conference: Infrared Diagnostics of Galaxy Evolution | 
	 
	
		| Page: | 
		128 | 
	 
	
		| Authors: | 
		Appleton, P.N.; Gil de Paz, A.; Madore, B.; Reach, W.; Struck, C.; Brandl, B.; Jarrett, T.; Fadda, D.; Charmandaris, V.; Armus, L.; Smith, B.; Mazzarella, J.; Lord, S.; Laine, S.; Borne, K. | 
	 
	
	
		| Abstract: | 
		We present some first results from a GALEX and Spitzer survey of a dozen collisional ring galaxies. The combination of UV and mid-IR imaging and spectroscopy will allow us to investigate the relationship between massive star formation sites, PAH molecular–band strengths, and dust heating in these mainly simultaneous starburst rings. A deep observation of the well-known Cartwheel ring galaxy has revealed a gigantic outer UV disk which extends to at least twice the radius of the outer blue star–forming ring. A lack of UV variability in the outer Cartwheel ring rules out an intermediate-mass black hole (IMBH) as the origin of the brightest of a dozen ULX source seen by Chandra in the ring. | 
	 
	
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