ESTIMATION OF GALAXY AGE BY MODIFIED MEYER AND SHRAMM NUCLEOSYNTHESIS MODEL

The independent model used by Meyer and Schramm (here after M&S) for determining the age of elements (chemical evolution) is extended. Using new and extended definitions and including parameters ignored by M&S, the galactic evolution equations are solved to determine the total duration of nucleosynthesis,T. To be able to calculate the t? T (mean age time for formation of elements to total duration of nucleosynthesis ratio), one event age, max ij ? , and r(i, j) are determined using approximation relating r?(i, j) to the former value r(i, j). For Th/U pair, constraint on t? T becomes 0.43 ? t? T ? 0.61 and the age of the galaxy is obtained as 12.5 23.0 Gal Gyr ? T ? Gyr , reducing the variation considerably compared to M&S formalism ( 8.7Gyr ? TGal ? 28.1 Gyr ). The range of constraints for the age of the universe is shorter than the M&S and our modifications on the model have reduced the interval for galaxy age 83% and close to being concordant with other available methods.