Star cluster formation and survival in the first galaxies
Star cluster formation and survival in the first galaxies
复制标题
第一个星系中的星团形成和生存
DOI：
10.1093/mnras/stad1092
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发表时间：
2023
影响因子：
4.8
通讯作者：
Park Jongwon
中科院分区：
文献类型：
--
作者：
Garcia Fred Angelo Batan;Ricotti Massimo;Sugimura Kazuyuki;Park Jongwon
利用辐射流体动力学宇宙学模拟，我们提供了一个典型质量矮星系在再电离时代之前的详细(0.1PC分辨率)物理激励的肖像，解决了星团形成和演化为单独的10M⊙恒星粒子的问题。在静止的紫外线图中，星系具有不规则的形态，没有凸起或圆盘，主要是从众多致密和引力约束的星团发出的光。这一点尤其令人感兴趣的是最近詹姆斯·韦伯太空望远镜的观测，−在引力透镜的放大能力的帮助下，以秒级的分辨率拍摄了在类似星系中形成的单个年轻星团的图像。由于它们的低金属度和高温，在这个星系中形成恒星的气体云的密度∼是典型的巨型分子云的100倍；因此，它们的预期恒星形成效率(SFE)足够高(约10−70%)，足以产生相当数量的潜在球状星团前体，但通常较小(几个100−2×104M⊙，半质量半径高达3pc)和较低的金属丰度(10−3.5-10−2.5Z⊙)。形成恒星的星云的初始质量函数是对数正态的，而束缚星团质量函数是一个幂函数，其斜率主要取决于SFE，但也取决于与主要恒星爆发的时间接近程度。根据假设的子网格−，我们得到了介于SFE0.5和−2.5之间的斜率。恒星的形成在星系尺度上是自我调节的；然而，星团的多峰金属丰度分布和被锁定在幸存的束缚星团中的恒星的比例取决于SFE。
Using radiation-hydrodynamic cosmological simulations, we present a detailed (0.1 pc resolution), physically motivated portrait of a typical-mass dwarf galaxy before the epoch of reionization, resolving the formation, and evolution of star clusters into individual 10 M⊙star particles. In the rest-frame ultraviolet, the galaxy has an irregular morphology with no bulge or disc, dominated by light emitted from numerous, compact, and gravitationally-bound star clusters. This is especially interesting in light of recentJames Webb Space Telescopeobservations that − aided by the magnifying power of gravitational lenses – have imaged, at parsec-scale resolution, individual young star clusters forming in similar galaxies atz> 6. Because of their low metallicities and high temperatures, star-forming gas clouds in this galaxy have densities ∼100 times higher than typical giant molecular clouds; hence, their expected star formation efficiencies (SFEs) are high enough (around 10 − 70 per cent) to produce a sizeable population of potential globular cluster progenitors, but typically smaller (a few 100 − 2 ×104M⊙, half-mass radii of up to 3 pc) and of lower metallicities (10−3.5– 10−2.5Z⊙). The initial mass function of the star-forming clouds is log-normal, whereas the bound star cluster mass function is a power-law with a slope that depends mainly on SFE but also on the temporal proximity to a major starburst. We find slopes between −0.5 and −2.5 depending on the assumed sub-grid SFE. Star formation is self-regulated on galactic scales; however, the multimodal metallicity distribution of the star clusters and the fraction of stars locked into surviving bound star clusters depends on SFE.