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Unformatted text preview: T = 12 Gyr in the Galactic plane in the solar neighborhood. Assuming the Schmidt SFR = g , determine the value of that will give the present gas fraction g ( T ) / T ( T ) = 0 . 24 at the present time. Hint: Note that df dt + f = e-t d dt fe t if is a constant. 3. Explain why the value of [O/Fe] observed in stars is both greater than 0 and does not vary with [Fe/H] for metal-decient stars for [Fe/H] <-1 . 5, but decreases with increasing metallicity for more metal-rich stars. When [Fe/H]=0, what value should [O/Fe] have? 4. Do problem 4.13 in the text....
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This note was uploaded on 01/25/2012 for the course AST 346 taught by Professor Lattimer during the Spring '11 term at SUNY Stony Brook.
- Spring '11