arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2104.10892astro-ph.GAastro-ph.SR
收藏

巨分子云中大质量恒星团簇形成的辐射流体力学模拟

Radiation hydrodynamics simulations of massive star cluster formation in giant molecular clouds

Hajime Fukushima, Hidenobu Yajima

备注：
28 pages, 28 figures, accepted for publication in MNRAS
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

通过三维辐射流体动力学模拟，研究了表面密度从$Σ_{\rm cl} = 80$到$3200~M_{\odot}\;{\rm pc^{-2}}$的年轻大质量星团（YMC，$M_{*}>10^4~M_{\odot}$）的形成过程。我们发现，光电离反馈抑制恒星形成显着的云与低表面密度。对于具有$M_{\rm cl}=10^{6}~M_{\odot}$和$Z= Z_{\odot}$的云，一旦初始表面密度超过$\sim 100~M_{\odot}\;{\rm pc^{-2}}$，大部分气体转化为恒星，因为光电离反馈在深引力势中效率低下。在这种情况下，星团是巨大的，引力束缚为YMC。过渡区表面密度随金属丰度的降低而增加，对于$Z=10^{-2}~Z_{\odot}$，过渡区表面密度为$\sim 350~M_{\odot}\;{\rm pc^{-2}}$。我们发现，超过10%的恒星形成效率（SFE）需要保持一个星团的引力约束，即使在云的破坏。此外，我们开发了一个半解析模型再现在我们的模拟中获得的SFE。我们发现，SFE符合幂律函数的依赖性$\propto Σ_{\rm cl}^{1/2}$低表面密度和迅速增加的过渡表面密度。表面密度和金属丰度的条件与最近在附近星系中观测到的形成YMC的巨大分子云相匹配。

英文摘要：

By performing three-dimensional radiation hydrodynamics simulations, we study the formation of young massive star clusters (YMCs, $M_{*}>10^4~M_{\odot}$) in clouds with the surface density ranging from $Σ_{\rm cl} = 80$ to $3200~M_{\odot}\;{\rm pc^{-2}}$. We find that photoionization feedback suppresses star formation significantly in clouds with low surface density. Once the initial surface density exceeds $\sim 100~M_{\odot}\;{\rm pc^{-2}}$ for clouds with $M_{\rm cl}=10^{6}~M_{\odot}$ and $Z= Z_{\odot}$, most of the gas is converted into stars because the photoionization feedback is inefficient in deep gravitational potential. In this case, the star clusters are massive and gravitationally bounded as YMCs. The transition surface density increases as metallicity decreases, and it is $\sim 350~M_{\odot}\;{\rm pc^{-2}}$ for $Z=10^{-2}~Z_{\odot}$. We show that more than 10 percent of star-formation efficiency (SFE) is needed to keep a star cluster gravitationally bounded even after the disruption of a cloud. Also, we develop a semi-analytical model reproducing the SFEs obtained in our simulations. We find that the SFEs are fit with a power-law function with the dependency $\propto Σ_{\rm cl}^{1/2}$ for low-surface density and rapidly increases at the transition surface densities. The conditions of the surface density and the metallicity match recent observations of giant molecular clouds forming YMCs in nearby galaxies.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑