Toroidal vortices and the conglomeration of dust into rings in protoplanetary discs
Toroidal vortices and the conglomeration of dust into rings in protoplanetary discs
复制标题
环形涡流和尘埃在原行星盘中聚集成环
DOI：
10.1093/mnrasl/slv109
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发表时间：
2015
影响因子：
4.8
通讯作者：
M. Bate
中科院分区：
文献类型：
--
作者：
P. Lorén;M. Bate
我们在原行星盘中发现了一种新的流体动力学不稳定性，它可能是由于尘气比的变化而产生的，并可能导致尘埃颗粒在盘中聚集。这种不稳定可能是由于尘埃沉降而引起的，这会产生垂直的成分熵梯度。熵梯度驱动了斜压不稳定，这种不稳定能够产生环状气体涡旋，将尘埃聚集成环。这样的尘埃环可能通过尘埃或散射光的连续发射而被观测到。事实上，这种不稳定性可能为最近在年轻恒星HL Tau和TW Hya周围的圆盘中观察到的环提供了一个解释，这些环不依赖于原行星的清理。这种不稳定性还可能有更广泛的影响，潜在地帮助尘埃聚集，改变较大小行星的径向迁移，并改变圆盘内的角动量传输。
We identify a new hydrodynamical instability in protoplanetary discs that may arise due to variations in the dust-to-gas ratio and may lead to concentration of dust grains within a disc. The instability can arise due to dust settling, which produces a vertical compositional entropy gradient. The entropy gradient drives a baroclinic instability that is capable of creating toroidal gas vortices that gather dust into rings. Such dust rings are potentially observable via continuum emission of the dust or scattered light. Indeed, this instability may offer an explanation for the rings recently observed in the discs around the young stars HL Tau and TW Hya that does not rely on clearing by protoplanets. The instability may also have wider ramifications, potentially aiding dust agglomeration, altering the radial migration of larger planetesimals, and modifying angular momentum transport within a disc.