宇宙生产的
Raul Jimenez1, Chris Flynn, James MacDonald
1Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA. raulj@physics.upenn.edu
概括
我们使用K矮星计算了与金属相对的的宇宙生产率. 我们的发现与H II区域数据和恒星产量预测一致,影响星际丰富.
科学领域:
- 天文学和天体物理学
- 恒星进化 恒星进化
- 太空化学 太空化学
背景情况:
- 和金属的宇宙丰富性为银河系的化学进化提供了洞察力.
- 精确测量产量对于理解恒星核合成和星际介质的丰富至关重要.
- 以前的产量估计依赖于各种方法,需要与独立数据集进行交叉验证.
研究的目的:
- 为了确定与金属 (DeltaY/DeltaZ) 相对的的宇宙生产率.
- 为此估计,利用Hipparcos目录中的K矮星,具有精确的光谱金属性.
- 为了将得出的DeltaY/DeltaZ值与来自H II区域的现有数据和理论恒星收益率预测进行比较.
主要方法:
- 从Hipparcos目录中选择K矮星.
- 获取和分析精确的光谱金属性为选定的恒星.
- 根据恒星数据计算与金属生产比率 (DeltaY/DeltaZ).
主要成果:
- 与金属相比,的宇宙生产率的最佳值被确定为DeltaY/DeltaZ = 2.1 +/- 0.4 在68%的置信水平下.
- 导出的DeltaY/DeltaZ值显示与H II区域的测量结果一致.
- 这些结果与基于恒星产量标准初始质量函数假设的理论预测一致.
结论:
- 该研究提供了与金属相对的生产率的可靠估计.
- 不同的测量方法 (恒星,H II区域,理论) 的一致性加强了我们对银河系化学进化的理解.
- 恒星中的丰富度会影响恒星的寿命和它们丰富星际介质的速度,影响未来的恒星形成.
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