ESTIMATION OF GALAXY AGE BY MODIFIED MEYER AND SHRAMM NUCLEOSYNTHESIS MODEL

• Published in: Iranian journal of science and technology. Transaction A, Science Science, 2009-06, Vol.33 (A3), p.225-233
• Main Authors: Eskandari, M R, Bahadoran, M
• Format: Article
• Language: English
• ISSN: 1028-6276

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 sub(v)/T (mean age time for formation of elements to total duration of nucleosynthesis ratio), one event age, Delta super(m) sub(i) super(a) sub(j) super(x), and r(i,j) are determined using approximation relating r'(i,j) to the former valuer(i, j). For Th/U pair, constraint on t sub(v)/T becomes 0.43 less than or equal to t sub(v)/T less than or equal to 0.61 and the age of the galaxy is obtained as 12.5 Gyr less than or equal to T sub(Gal) less than or equal to 23.0 Gyr, reducing the variation considerably compared to M&S formalism (8.7Gyr less than or equal to T sub(Gal) less than or equal to 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.