论文标题
建模磁盘和磁流出围绕形成的大量恒星：ii。大量原始恒星的喷气机的动力学
Modeling disks and magnetic outflows around a forming massive star: II. Dynamics of jets from massive protostars
论文作者
论文摘要
形成巨大的恒星会引发磁性原状的流出，实际上是寻找巨大恒星形成部位的标记。但是，只有直到近年来才有可能干预这种流出形成和传播的机制的理论和观察性研究。通过这项工作，我们旨在详细研究从大型恒星形成的早期阶段驱动高度准直的流出的机制，以及这些过程如何受到形成大型恒星的出生环境的特性的影响。我们执行一系列31个模拟，目的是构建这些机制的统一理论图片，并查看不同环境的影响如何改变其形态和动量输出。磁性水力学模拟还将欧姆耗散视为非理想效应，自重和扩散的辐射传输，用于粉尘和气体的热吸收和发射。我们从由最初均匀的磁场螺纹并缓慢旋转的崩溃云芯开始。我们在球形坐标中利用二维轴对称网格。在模拟中，我们可以清楚地区分快速的，磁中心的发射和准直的射流（速度> 100 km/s的速度）与由磁性压力驱动的较宽的磁性塔流动，该磁力会及时扩大。我们详细分析了流动的加速度，并通过数百个天文单元的距离发生的磁力重新汇总。我们量化了磁制动在流出中的影响，从而缩小了系统晚期进化的流出腔。我们观察到在大规模原始原始恒星的出生环境中的广泛假设中存在相同的喷气驾驶机制，但随着时间的流逝，它们的形态和机械反馈变为更大的尺度。
Forming massive stars launch outflows of magnetic origin, which in fact serve as a marker for finding sites of massive star formation. However, both the theoretical and observational study of the mechanisms that intervene in the formation and propagation of such outflows has been possible only until recent years. With this work, we aim to study in detail the mechanisms that drive highly collimated outflows from early stages of the formation of a massive star, and how those processes are impacted by the properties of the natal environment of the forming massive star. We perform a series of 31 simulations with the aim of building a unified theoretical picture of these mechanisms, and see how the impact of different environments alter their morphology and momentum output. The magnetohydrodynamical simulations consider also Ohmic dissipation as a nonideal effect, self-gravity, and diffusive radiation transport for thermal absorption and emission by the dust and gas. We start from a collapsing cloud core that is threaded by an initially-uniform magnetic field and which is slowly rotating. We utilize a two-dimensional axisymmetric grid in spherical coordinates. In the simulations, we can clearly distinguish a fast, magneto-centrifugally launched and collimated jet (of speeds > 100 km/s), from a wider magnetic tower flow driven by magnetic pressure which broadens in time. We analyze in detail the acceleration of the flow, and its re-collimation by magnetic forces happening at distances of several hundreds of astronomical units. We quantify the impact of magnetic braking in the outflows, which narrows the outflow cavity for the late evolution of the system. We observe the presence of the same jet-driving mechanisms for a wide range of assumptions on the natal environment of the massive protostar, but with changes to their morphology and mechanical feedback into larger scales over time.
