论文标题
$^{26} $ al和$^{60} $ fe的化学演变以银河系方式
Chemical evolution of $^{26}$Al and $^{60}$Fe in the Milky Way
论文作者
论文摘要
我们介绍了$^{26} $ al和$^{60} $ fe的理论质量估计，并在整个银河系中进行，并采用数值化学演化模型进行，其中包括用于稳定和放射性核素的详细核合成处方。我们比较了从文献中获取的几组恒星收益率的结果，对于大量，低和中间的质量星，Nova系统（仅用于$^{26} $ Al）和Supernovae Type IA。然后，我们计算出$^{26} $ al和$^{60} $ FE的总质量。我们研究了Galactactric半径范围0-22 kpc的凸起和圆盘。我们假设凸起区域（2 kpc之内）迅速发展出强烈的恒星形成爆发，而圆盘的形成更慢，内而外。我们将我们的结果与$^{26} $ al质量进行了比较，由$γ$ -Ray调查comptel和积分不可或缺的组成部分，以选择最佳型号。关于$^{60} $ fe，我们没有观察到的质量价值，因此我们只是为将来的观察做出了理论预测。总之，低的，中间的质量恒星和IA型超新星对两个同位素的贡献无可忽视，而大型恒星是主要的来源。但是，必须贡献Nova的贡献是重现$^{26} $ al的观察结果。我们的最佳模型预测$ 2.12 $ m $ _ {\ odot} $的$^{26} $ al，与观测一致，而对于$^{60} $ fe，我们的最佳质量估计为$ \ sim 1.05 $ m $ _ $ _ {\ odot} $。我们还预测了$^{26} $ al和$^{60} $ fe的目前注射率，并将其与先前的结果进行了比较，我们发现沿光盘沿线的当前时间注入率更高。
We present theoretical mass estimates of $^{26}$Al and $^{60}$Fe throughout the Galaxy, performed with a numerical chemical evolution model including detailed nucleosynthesis prescriptions for stable and radioactive nuclides. We compared the results for several sets of stellar yields taken from the literature, for massive, low and intermediate mass stars, nova systems (only for $^{26}$Al) and supernovae Type Ia.We then computed the total masses of $^{26}$Al and $^{60}$Fe in the Galaxy. We studied the bulge and the disc of the Galaxy in a galactocentric radius range 0-22 kpc. We assumed that the bulge region (within 2 kpc) evolved quickly suffering a strong star formation burst, while the disc formed more slowly and inside-out. We compared our results with the $^{26}$Al mass observed by the $γ$-ray surveys COMPTEL and INTEGRAL to select the best model. Concerning $^{60}$Fe, we do not have any observed mass value so we just performed a theoretical prediction for future observations. In conclusion, low, intermediate mass stars and Type Ia supernovae contribute negligibly to the two isotopes, while massive stars are the dominant source. The nova contribution is, however, necessary to reproduce the observations of $^{26}$Al. Our best model predicts $2.12$ M$_{\odot}$ of $^{26}$Al, in agreement with observations, while for $^{60}$Fe our best mass estimate is $\sim 1.05$ M$_{\odot}$. We also predicted the present injection rate of $^{26}$Al and $^{60}$Fe in the Galaxy and compared it with previous results, and we found a larger present time injection rate along the disc.
