EAPSI: Studying the first light in the early universe

当宇宙历史上的第一批恒星形成时，它们开始发出光，即光子。人们相信，这种光可以用红外望远镜从天空的各个方向观测到微弱的辉光。测量这种微弱的光，被称为宇宙近红外背景（NIRB），可以被认为是间接地观察到最初的光源。韩国光州朝鲜大学（Chosun University）的安敬镇（Kyung-jin Ahn）教授最近进行了一次高分辨率的宇宙模拟，捕捉到了第一批光源的形成过程。通过这些模拟，将建立第一个源及其周围环境的特性与观测到的NIRB之间的联系。这项研究将研究第一个光源与NIRB之间的关系。通过研究这种相互关系，我们可以更好地了解宇宙的历史。研究宇宙将为无法通过地球上的实验来研究的物理学提供检验，从而导致人类知识和技术发展的进一步进步。有了这个数据集，将计算得到的光谱，然后与实际观测结果进行比较。此外，由于某些因素，如恒星形成速率、产生的光子数量和初始质量函数，是事先已知的，因此可以准确地理解这些参数如何在NIRB中表现出来。对这些参数施加更严格的限制也将有助于更好地理解另一种天体物理事件——宇宙再电离，即宇宙从充满中性氢转变为电离等离子体的海洋。美国国家科学基金会EAPSI奖与韩国国家研究基金会合作资助。

When the first stars in the history of the universe were formed, they began to emit light, known as photons. It is believed that this light can be observed as a faint glow that is seen in every direction in the sky using infrared telescopes. Measuring this faint glow, referred to as the Cosmic Near-Infrared Background (NIRB), can be thought of as indirectly looking at the first sources of light. Professor Kyung-jin Ahn at Chosun University in Gwangju, South Korea, has recently run a high-resolution cosmological simulation that captures the formation of the first sources of light. Using these simulations, the connections between the properties of the first sources and their surroundings and the observed NIRB will be made. This research will study the correlation between the first sources of light and the NIRB. In studying this correlation, a better understanding about the history of the universe can be gained. Studying the universe will provide tests for physics that cannot be studied through experimentation on Earth, thereby leading to further advancements in human knowledge and technological developments.With this dataset, the resulting spectrum will be calculated, which can then be compared with the actual observations. Furthermore, because certain factors, such as star formation rates, the number of photons produced, and the initial mass function, are known in advance, precisely how these parameters manifest themselves in the NIRB can be understood. Putting a tighter limit on these parameters will also lead to a better understanding of a different astrophysical event, Cosmic Reionization, when the universe transformed from being filled with neutral hydrogen to a sea of ionized plasma. This NSF EAPSI award is funded in collaboration with the National Research Foundation of Korea.