Galactic Chemical Evolution: The 3-Helium Problem

对元素起源和演化的研究是现代天体物理学的基石之一。对于任何给定的同位素，确定其丰度以及丰度如何在时间和空间上变化至关重要。了解氦3同位素的宇宙丰度具有广泛的跨学科影响：氦3可以用来测试恒星核合成理论;氦3提供了评估银河系化学演化模型所需的重要信息;氦3可以帮助限制大爆炸核合成。 Bania博士（波士顿大学）和他的团队将使用国家射电天文台（NRAO）的绿色银行望远镜，NRAO的超大阵列，国家天文和电离层中心的阿雷西博天文台以及澳大利亚望远镜国家设施的帕克斯天文台观测少量，约10个新的3 He源。 具体的问题可以通过这些仪器现在所具有的增强的光谱灵敏度来回答。 只要再多几个，战略性地选择3 He来源就可以对解决我们对宇宙3 He丰度的理解产生巨大影响。3 He丰度本身就涉及到广泛的天体物理学重要问题。它探讨了宇宙本身的创造和演化，这个话题直接涉及公众对我们起源的理解。 除了培训下一代射电天文学家，巴尼亚博士和他的团队将继续改进探测弱微波谱线的技术。

The study of the origin and evolution of the elements is one of the cornerstones of modern astrophysics. For any given isotope it is crucial to determine its abundance and how that abundance varies temporally and spatially. Knowing the cosmic abundance of the 3He isotope has a broad interdisciplinary impact: 3He can be used to test the theory of stellar nucleosynthesis; 3He gives important information needed to evaluate models of Galactic chemical evolution; 3He can help constrain Big Bang Nucleosynthesis. Dr. Bania (Boston University) and his team will observe a small number, ~10, of new 3He sources with the National Radio Astronomy Observatory's (NRAO) Green Bank Telescope, NRAO's Very Large Array, the National Astronomy and Ionosphere Center's Arecibo Observatory, and the Australia Telescope National Facility's Parkes Observatory. Specific questions can be answered by the enhanced spectroscopic sensitivity now available with these instruments. Just a few more, strategically chosen 3He sources can have a great impact in resolving our understanding of the cosmic 3He abundance. The 3He abundance itself speaks to a wide range of astrophysically important issues. It probes the creation and evolution of the Universe itself, a topic that speaks directly to the public's quest for an understanding of our origins. In addition to training the next generation of radio astronomers, Dr. Bania and his team shall continue to improve techniques for detecting weak microwave spectral lines.