Protostellar collapse: the conditions to form dust-rich protoplanetary disks
Protostellar collapse: the conditions to form dust-rich protoplanetary disks
复制标题
原恒星塌缩：形成富含尘埃的原行星盘的条件
DOI：
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发表时间：
2020
影响因子：
6.5
通讯作者：
G. Laibe
中科院分区：
文献类型：
--
作者：
U. Lebreuilly;B. Commerccon;G. Laibe
上下文尘埃在星星、盘和行星的形成过程中起着关键作用。然而，它在原恒星坍缩过程中的动力学仍然是一个研究不足的领域。最近的研究似乎表明，在这些早期阶段，尘埃可能会有效地与气体分离。
目标。我们的目标是了解在原恒星坍缩的早期阶段，尘埃颗粒集中在多少和哪些区域，并了解这如何取决于初始云和固体颗粒的性质。
方法.我们使用基于网格的代码RAMSES的多物种尘埃动力学MULTIGRAIN求解器来执行尘埃塌陷的各种模拟。我们进行了流体动力学和磁流体动力学模拟，其中我们改变了尘埃分布的最大尺寸，热引力能量比和云的磁性。我们模拟了10个中性尘埃颗粒物种的同时演化，其颗粒尺寸从几纳米到几百微米不等。
结果我们得到一个显着的解耦之间的气体和灰尘的颗粒的典型尺寸为几十微米。这种退耦强烈依赖于热引力能量比、晶粒尺寸和磁场的存在。与半解析模型校准我们的结果，我们表明，尘埃比主要是指数变化的初始斯托克斯数的速率，取决于当地的云属性。
结论.我们发现，较大的晶粒往往解决和漂移有效地在第一个核心和新形成的磁盘。这可能会产生数倍于初始值的粉尘与气体比率。尘埃集中在高密度区域（核心，磁盘和伪磁盘），并在低密度区域（信封和流出）耗尽。颗粒与气体分离的大小取决于云的初始性质。由于尘埃不一定被用来作为气体的代理在崩溃，我们强调的必要性，包括处理其动力学在原恒星坍缩模拟。
Context. Dust plays a key role during star, disk, and planet formation. Yet, its dynamics during the protostellar collapse remain a poorly investigated field. Recent studies seem to indicate that dust may decouple efficiently from the gas during these early stages.
Aims. We aim to understand how much and in which regions dust grains concentrate during the early phases of the protostellar collapse, and to see how this depends on the properties of the initial cloud and of the solid particles.
Methods. We used the multiple species dust dynamics MULTIGRAIN solver of the grid-based code RAMSES to perform various simulations of dusty collapses. We performed hydrodynamical and magnetohydrodynamical simulations where we varied the maximum size of the dust distribution, the thermal-to-gravitational energy ratio, and the magnetic properties of the cloud. We simulated the simultaneous evolution of ten neutral dust grain species with grain sizes varying from a few nanometers to a few hundreds of microns.
Results. We obtain a significant decoupling between the gas and the dust for grains of typical sizes of a few tens of microns. This decoupling strongly depends on the thermal-to-gravitational energy ratio, the grain sizes, and the inclusion of a magnetic field. With a semi-analytic model calibrated on our results, we show that the dust ratio mostly varies exponentially with the initial Stokes number at a rate that depends on the local cloud properties.
Conclusions. We find that larger grains tend to settle and drift efficiently in the first-core and in the newly formed disk. This can produce dust-to-gas ratios of several times the initial value. Dust concentrates in high-density regions (cores, disk, and pseudo-disk) and is depleted in low-density regions (envelope and outflows). The size at which grains decouple from the gas depends on the initial properties of the clouds. Since dust cannot necessarily be used as a proxy for gas during the collapse, we emphasize the necessity of including the treatment of its dynamics in protostellar collapse simulations.
影响因子：
6.5
作者：
Ł. Tychoniec;C. Manara;G. Rosotti;E. V. van Dishoeck;A. Cridland;T. Hsieh;N. Murillo;D. Segura-Cox-D.-Se
通讯作者：
Ł. Tychoniec;C. Manara;G. Rosotti;E. V. van Dishoeck;A. Cridland;T. Hsieh;N. Murillo;D. Segura-Cox-D.-Se
利用毫米波偏振研究过渡盘中的灰尘捕集
DOI：
10.1051/0004-6361/201628637
发表时间：
2016
期刊：
arXiv: Earth and Planetary Astrophysics
影响因子：
--
作者：
Kataoka;Pinilla;Dullemond;Henning;Birnstiel
通讯作者：
Birnstiel