Galactic Chemical Evolution: The 3-Helium Problem

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，确定其丰度以及该丰度在时间和空间上的变化是至关重要的。了解3He同位素的宇宙丰度具有广泛的跨学科影响：3He可用于测试恒星核合成理论；3He提供评估银河系化学演化模型所需的重要信息；3He可帮助限制大爆炸核合成。巴尼亚博士(波士顿大学)和他的团队将利用国家射电天文台(NRAO)的绿岸望远镜、NRAO的甚大阵列、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、~10个新的3He源。具体的问题可以通过这些仪器现在提供的增强的光谱灵敏度来回答。只要再多几个，策略性地选择3He源就可以对解决我们对宇宙3He丰度的理解产生巨大的影响。3He丰度本身就说明了一系列重要的天体物理问题。它探讨了宇宙本身的创造和进化，这是一个直接与公众对理解我们的起源的探索有关的话题。除了培训下一代射电天文学家，巴尼亚博士和他的团队还将继续改进探测微弱微波谱线的技术。

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.