Galactic chemical evolution of light elements

4 Galactic chemical evolution of light elements 9.4.1 Introduction 

Using the instantaneous recycling approximation (Section 7.4.2), Eq. (7.33) now has to be replaced by 

Results for the Simple model are shown in Fig. 9.5. Oxygen abundance simply increases in proportion to u, whereas that of 7Li starts from a finite base and tends to a limiting value p].,/(a l — 1) owing to its eventual destruction by astration. Deuterium (p = 0 in Eq. 9.25) suffers little destruction as long as the oxygen abundance (or metallicity) is less than about 0.1 of the true yield (assumed to be comparable to solar abundance), e.g. in high-redshift absorption-line clouds, but 

1 Z (7Li). The long-dashed curve indicates deuterium depletion in the simple inflow model. 

Using the simplest inflow model of Section 8.5.2, our assumptions are  

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Galactic chemical evolution of light elements Table 9.2. Results of simple calculations of light element abundances... 

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