论文标题
年轻的星团簇驱逐出生气体的速度？
How fast do young star clusters expel their natal gas?: Estimating the upper limit of the gas expulsion time-scale
论文作者
论文摘要
在嵌入式恒星簇中形成巨大的恒星在它们的反馈，流动气体和恒星动力学之间开始了复杂的相互作用，这些动力通常包括紧密的恒星遭遇。流体动力学模拟通常逐步简化模型，以模拟嵌入式簇。在这里，我们解决了通过单个水槽粒子近似整个恒星簇的简化，该粒子完全忽略了内部恒星动力学。为了对内部恒星动力学进行建模，我们对流体动力代码闪光灯实现了HERMITE预测器 - 校准集成方案。正如我们通过一系列测试所说明的那样，该集成器显着优于当前的Leap-Frog方案，并且能够遵循小型紧凑型恒星系统的动力学，而无需软化重力电位。 We find that resolving individual massive stars instead of representing the whole cluster by a single energetic source has a profound influence on the gas component: for clusters of mass less than $\lesssim 3 \times 10^3 M_{\odot}$, it slows gas expulsion by a factor of $\approx 5$ to $\approx 1$ Myr, and it results in substantially more complex gas structures.随着群集质量的增加（最多$ \ 3 \ times 10^3 m _ {\ odot} $），气体驱动时间尺度略有下降。但是，更大的群集（$ \ gtrsim 5 \ times 10^3 m _ {\ odot} $）只有在光电离电辐射和恒星风中以$ 1/3 $形成恒星形成效率（SFE）时，才能使用光电发电辐射和恒星风清除其自然气体。这意味着更大的群集要么用另一种反馈机制清除，要么以高于$ 1/3 $的SFE形成。
Formation of massive stars within embedded star clusters starts a complex interplay between their feedback, inflowing gas and stellar dynamics, which often includes close stellar encounters. Hydrodynamical simulations usually resort to substantial simplifications to model embedded clusters. Here, we address the simplification which approximates the whole star cluster by a single sink particle, which completely neglects the internal stellar dynamics. In order to model the internal stellar dynamics, we implement a Hermite predictor-corrector integration scheme to the hydrodynamic code FLASH. As we illustrate by a suite of tests, this integrator significantly outperforms the current leap-frog scheme, and it is able to follow the dynamics of small compact stellar systems without the necessity to soften the gravitational potential. We find that resolving individual massive stars instead of representing the whole cluster by a single energetic source has a profound influence on the gas component: for clusters of mass less than $\lesssim 3 \times 10^3 M_{\odot}$, it slows gas expulsion by a factor of $\approx 5$ to $\approx 1$ Myr, and it results in substantially more complex gas structures. With increasing cluster mass (up to $\approx 3\times 10^3 M_{\odot}$), the gas expulsion time-scale slightly decreases. However, more massive clusters ($\gtrsim 5\times 10^3 M_{\odot}$) are unable to clear their natal gas with photoionising radiation and stellar winds only if they form with a star formation efficiency (SFE) of $1/3$. This implies that the more massive clusters are either cleared with another feedback mechanism or they form with a SFE higher than $1/3$.
