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 ofelements (chemical evolution) is extended. using new and extended definitions and including parametersignored by m&s, the galactic evolution equations are solved to determine the total duration ofnucleosynthesis,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 considerablycompared to m&s formalism ( 8.7gyr  tgal  28.1 gyr ). the range of constraints for the age of theuniverse 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.