近日，瑞典斯德哥尔摩大学的Angela Adamo及其研究团队取得一项新进展。经过不懈努力，他们在大爆炸后4.6亿年透镜星系中观测到束缚星团。相关研究成果已于2024年6月24日在国际权威学术期刊《自然》上发表。

该研究团队报道了JWST对宇宙宝石的观测。星系的光被分解成五个星团，它们位于一个小于70秒差距的区域。它们表现出最小的尘埃衰减和低金属丰度，年龄小于5000万年，固有质量为约为10⁶ M⊙。它们经过透镜校正后的大小约为1pc，导致恒星表面密度接近10⁵ M_⊙ /pc²，比当地宇宙中典型的年轻星团高出三个数量级。尽管透镜模型存在固有的不确定性，但它们与引力束缚的恒星系统一致，即原球状星团(proto-GCs)。研究人员得出结论，星团的形成和反馈可能有助于在再电离时期塑造星系的性质。

据悉，宇宙宝石弧是在红移z约 10.2处观测到的最明亮和高度放大的星系之一。然而，它本质上是一个紫外线微弱的星系，在那些现在被认为驱动宇宙再电离的星系的范围内。迄今为止，在类似红移的星系中，最小的特征在几百到几十秒差距（pc)之间。

附：英文原文

Title: Bound star clusters observed in a lensed galaxy 460 Myr after the Big Bang

Author: Adamo, Angela, Bradley, Larry D., Vanzella, Eros, Claeyssens, Adlade, Welch, Brian, Diego, Jose M., Mahler, Guillaume, Oguri, Masamune, Sharon, Keren, Abdurrouf, Hsiao, Tiger Yu-Yang, Xu, Xinfeng, Messa, Matteo, Lassen, Augusto E., Zackrisson, Erik, Brammer, Gabriel, Coe, Dan, Kokorev, Vasily, Ricotti, Massimo, Zitrin, Adi, Fujimoto, Seiji, Inoue, Akio K., Resseguier, Tom, Rigby, Jane R., Jimnez-Teja, Yolanda, Windhorst, Rogier A., Hashimoto, Takuya, Tamura, Yoichi

Issue&Volume: 2024-06-24

Abstract: The Cosmic Gems arc is among the brightest and highly magnified galaxies observed at redshift z ～ 10.2. However, it is an intrinsically UV faint galaxy, in the range of those now thought to drive the reionization of the universe. Hitherto the smallest features resolved in a galaxy at a comparable redshift are between a few hundreds and a few tens of parsecs. Here we report JWST observations of the Cosmic Gems. The light of the galaxy is resolved into five star clusters located in a region smaller than 70 parsec. They exhibit minimal dust attenuation and low metallicity, ages younger than 50 Myr and intrinsic masses of ～ 10⁶ M_⊙. Their lensing-corrected sizes are approximately 1 pc, resulting in stellar surface densities near 10⁵ M_⊙ /pc², three orders of magnitude higher than typical young star clusters in the local universe. Despite the uncertainties inherent to the lensing model, they are consistent with being gravitationally bound stellar systems, i.e., proto-globular clusters (proto-GCs). We conclude that star cluster formation and feedback likely contributed to 3 shape the properties of galaxies during the epoch of reionization.

DOI: 10.1038/s41586-024-07703-7

Source: https://www.nature.com/articles/s41586-024-07703-7