近日，英国萨里大学Ethan D. Taylor团队揭示了球状星团和球状星团样矮星的出现。这一研究成果于2025年9月10日发表在《自然》杂志上。

球状星团（GCs）是宇宙中最古老、密度最大的恒星系统之一，但它们是如何形成的仍然是一个谜。

研究组提出了一套宇宙学模拟，其中不含暗物质的GCs和富含暗物质的矮星系在标准宇宙学中自然出现。他们发现，这些天体位于尺寸-光度平面上的不同位置，其年龄、年龄分布、金属丰度和金属丰度分布与附近宇宙中的球状星团和矮星相似。在该模拟的球状星团中，大约有一半通过在宿主矮星中心附近的规则恒星形成，其余的则由合并引发进一步形成。后者在潮汐上更为孤立，更有可能存活至今。

最后，该模型预测了一类新天体的存在，研究组称之为“球状星团样矮星”（GCDs）。GCD由高红移处低质量暗物质晕中的单个自淬灭恒星形成事件形成，其观测特性介于球状星团和矮星之间。研究组在银河系中发现了几颗矮星，比如Reticulum II，它们可能属于这类新天体。如果是这样，他们将会对暗物质模型和寻找无金属恒星的新位置进行前所未有的约束。

附：英文原文

Title: The emergence of globular clusters and globular-cluster-like dwarfs

Author: Taylor, Ethan D., Read, Justin I., Orkney, Matthew D. A., Kim, Stacy Y., Pontzen, Andrew, Agertz, Oscar, Rey, Martin P., Andersson, Eric P., Collins, Michelle L. M., Yates, Robert M.

Issue&Volume: 2025-09-10

Abstract: Globular clusters (GCs) are among the oldest and densest stellar systems in the Universe, yet how they form remains a mystery1. Here we present a suite of cosmological simulations in which both dark-matter-free GCs and dark-matter-rich dwarf galaxies naturally emerge in the Standard Cosmology. We show that these objects inhabit distinct locations in the size–luminosity plane and that they have similar ages, age spread, metallicity and metallicity spread to globulars and dwarfs in the nearby Universe. About half of our simulated globulars form by means of regular star formation near the centres of their host dwarf, with the rest forming further out, triggered by mergers. The latter are more tidally isolated and more likely to survive to the present day. Finally, our simulations predict the existence of a new class of object that we call ‘globular-cluster-like dwarfs’ (GCDs). These form from a single, self-quenching, star-formation event in low-mass dark-matter halos at high redshift and have observational properties intermediate between globulars and dwarfs. We identify several dwarfs in our Galaxy, such as ReticulumII (refs.2,3,4), that could be in this new class. If so, they promise unprecedented constraints on dark-matter models and new sites to search for metal-free stars.

DOI: 10.1038/s41586-025-09494-x

Source: https://www.nature.com/articles/s41586-025-09494-x