论文标题
原始塌陷:角度动量和离子前体的发作的调节
Protostellar collapse: regulation of the angular momentum and onset of an ionic precursor
论文作者
论文摘要
通过磁制动和原恒星流出的发射,磁场在恒星形成中角动量的调节中起着重要作用,这直接影响了原球磁盘和二进制系统的形成和演变。本文的目的是在存在非理想的磁水动力学效应的情况下量化这些现象,即欧姆和Ambipola R扩散。我们对原恒星的三维模拟进行了三维模拟,以变化,以不同的质量核心核心,热支撑($α$比例)和灰尘晶粒尺寸 - 散布。质量主要影响伪盘中的磁制动,而热支持会影响吸积率,从而影响磁盘的性质。在Mathis,Rumpl,Nordsieck(MRN)分布中删除小于0的谷物,可增强双相扩散系数。与以前的研究类似,我们发现分布的这种变化减少了磁铁IC制动并对磁盘产生影响。流出也显着削弱。无论哪种情况,磁制动都在很大程度上占主导地位,作为从磁盘中去除角动量的过程。最后,我们向流出速度提供了一个大的离子前体,其速度为几个km s $^{ - 1} $,可以观察到。
Through the magnetic braking and the launching of protostellar outflows, magnetic fields play a major role in the regulation of angular momentum in star formation, which directly impacts the formation and evolution of protoplanetary disks and binary systems. The aim of this paper is to quantify those phenomena in the presence of non-ideal magnetohydrodynamics effects, namely the Ohmic and ambipola r diffusion. We perform three-dimensional simulations of protostellar collapses varying the mass of the prestellar dense core, the thermal support (the $α$ ratio) and the dust grain size-distribu tion. The mass mostly influences the magnetic braking in the pseudo-disk, while the thermal support impacts the accretion rate and hence the properties of the disk. Removing the grains smaller than 0. 1 $μ$m in the Mathis, Rumpl, Nordsieck (MRN) distribution enhances the ambipolar diffusion coefficient. Similarly to previous studies, we find that this change in the distribution reduces the magnet ic braking with an impact on the disk. The outflow is also significantly weakened. In either case, the magnetic braking largely dominates the outflow as a process to remove the angular momentum from t he disk. Finally, we report a large ionic precursor to the outflow with velocities of several km s$^{-1}$, which may be observable.