The interaction of cosmic fullerenes with their environment:confronting models with observations

2021年10月31日，詹姆斯·韦伯太空望远镜（JWST）发射后不久，加拿大天文学家将成为首批使用人类历史上最灵敏、最强大的天空眼睛研究红外（IR）宇宙的科学家之一。在JWST将提供的许多令人惊叹的图像中，编码的是一种独特的碳质化合物的指纹：巴基球——一种由60个碳原子排列成足球形状的化合物。巴基球是太空中已知的最大的分子，它们是“芳香”分子中唯一被确认的成员——这种分子的微观结构类似于蜂窝图案。芳香分子含有宇宙中15%的碳。它们的结构赋予了它们“超能力”，使它们能够在太空中一些最恶劣、高度辐射的环境中茁壮成长。事实上，它们变成了多产的分子机器，有效地将高能紫外线辐射转化为能量较低的红外光，它们还可以根据条件要求喷射或捕获电子或氢原子。这使它们成为一类超稳定的物种，通过改变辐射场和气体温度，进一步显著影响它们周围的环境。因此，这些微观粒子在恒星形成和星系演化等大规模过程中起着关键作用。然而，虽然我们在许多不同的宇宙环境中看到了巴基球，但我们不知道它们是如何形成的，而且我们对导致它们在红外波段发光的物理过程也不完全了解。这将随着JWST的观测而改变。它的视觉非常敏锐，可以很容易地精确定位巴基球的发射位置。它还将为我们提供有关这些地点的物理条件的详细信息，以及巴基球指纹的精细光谱特征。我将分析不同天体物理对象的观测结果，并创建模型，从根本上理解导致这些观测到的光谱特征的物理过程。由于同样的过程会影响太空中所有的芳香物种，因此提出的研究将大大提高对宇宙有机库存的理解，特别是在恒星和行星形成的区域，以及星际介质的演化，从而星系的演化。

Shortly after the James Webb Space Telescope (JWST) launches on October 31st, 2021, Canadian astronomers will be among the first scientists to study the infrared (IR) Universe using the most sensitive and powerful eyes on the skies in human history. Encoded in the many breathtaking images that JWST will provide, are the fingerprints of a unique carbonaceous compound: buckyballs - a compound made of 60 carbon atoms arranged in the shape of a soccer balls. Buckyballs are the largest molecules known in space, and they are the only identified members of the "aromatic" molecules - species whose microscopic structure resembles honeycomb patterns. Aromatic molecules contain about 15% of all the carbon in the Universe. Their structure gives them "superpowers" that allow them to thrive especially well in some of the harshest, highly irradiated environments in space. In fact, they turn into productive molecular machines that efficiently convert high-energy UV radiation into lower energy infrared light, and they can also eject or capture electrons or hydrogen atoms as the conditions demand. This makes them a class of super-stable species that furthermore significantly affect their immediate surroundings by changing the radiation field and the temperature of the gas. Consequently, these microscopic particles play key roles in large-scale processes such as star formation and galaxy evolution. However, while we have seen buckyballs in many different cosmic environments, we do not know how they form, and we have an incomplete understanding of the physical processes that cause them to glow in the IR. This will change owing to observations with the JWST. Its vision is so sharp, that it can easily pinpoint precisely where buckyballs are emitting. It will also provide us with detailed information about the physical conditions at those locations as well as exquisitely detailed spectral characteristics of the buckyball's fingerprints. I will analyze those observations for different astrophysical objects, and create models to fundamentally understand the physical processes that lead to these observed spectral characteristics. Since the same processes will affect all aromatic species in space, the proposed research will lead to a much improved understanding of the cosmic organic inventory, especially in regions of star and planet formation, and of the evolution of the interstellar medium and thus the evolution of galaxies.