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		| Paper: | 
		The [Fe/O] Ratio in Field Stars and the History of Star Formation of the Solar Neighbourhood | 
	 
	
		| Volume: | 
		92, Formation of the Galactic Halo. . . . Inside and Out | 
	 
	
		| Page: | 
		307 | 
	 
	
		| Authors: | 
		Gratton, Raffaele; Carretta, Eugenio; Matteucci, Francesca; Sneden, Christopher | 
	 
	
	
		| Abstract: | 
		From a reanalysis of O and Fe abundances in a large sample of stars in the solar neighbourhood, we found that the Fe/O abundance ratio is nearly constant in the (inner) halo and the thick disk. Within a homogeneous collapse scenario, this means that the timescale for halo collapse was <=\ the typical lifetime of type Ia SNe progenitors ( ~ 1 Gyr). The Fe/O ratio raised by ~ 0.2 dex while the O/H ratio hold constant during the transition from the thick to thin disk phases, indicating a sudden decrease in star formation in the solar neighbourhood at that epoch. | 
	 
	
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