| تعداد نشریات | 24 |
| تعداد شمارهها | 912 |
| تعداد مقالات | 8,158 |
| تعداد مشاهده مقاله | 15,836,144 |
| تعداد دریافت فایل اصل مقاله | 13,332,056 |
ESTIMATION OF GALAXY AGE BY MODIFIED MEYER AND SHRAMM NUCLEOSYNTHESIS MODEL | ||
| Iranian Journal of Science | ||
| مقاله 2، دوره 33، شماره 3، آذر 2009، صفحه 225-233 اصل مقاله (210.07 K) | ||
| نوع مقاله: Regular Paper | ||
| شناسه دیجیتال (DOI): 10.22099/ijsts.2009.2218 | ||
| نویسندگان | ||
| M. R. ESKANDARI* ؛ M. BAHADORAN | ||
| Islamic Azad University, Shiraz Branch, I. R. of Iran | ||
| چکیده | ||
| 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. | ||
| کلیدواژهها | ||
| Nucleosynthesis؛ cosmochronology؛ age of universe؛ independent model؛ galaxy evolution؛ chronometric pairs؛ abundances | ||
|
آمار تعداد مشاهده مقاله: 1,496 تعداد دریافت فایل اصل مقاله: 777 |
||