发表机构
Flatiron Institute; Ludwig-Maximilians-Universität München; Max-Planck-Institut für Astronomie; Columbia University; Stony Brook University（平顿研究所; 慕尼黑路德维希-马克西米利安大学; 马克斯·普朗克天文学研究所; 哥伦比亚大学; 石溪大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
模拟表明，考虑尘埃凝聚、沉降和热适应后，VSI减弱，可解释Class II盘的薄盘形态，且VSI可能仅限于Class I阶段。
AI 中文摘要
已知垂直剪切不稳定性（VSI）在热弛豫足够快时会在原行星盘中产生湍流和强烈的垂直混合。在满足此条件的模拟中，VSI可以将尘埃颗粒提升到高海拔，在模拟毫米波观测中形成垂直延伸的外观，这与大多数观测到的Class II盘的形态不一致。我们展示了与观测到的薄盘几何形状一致的、含VSI的原行星盘模拟，同时保持了在微米波长散射光图像中常见的碗状形态。我们表明，当考虑尘埃凝聚、沉降以及尘埃-气体热适应的效应时，这一结果自然出现。沉降驱动的凝聚从盘大气中移除了大量尘埃，在此过程中减缓了尘埃驱动的气体冷却。同时，形成了毫米大小颗粒的致密中平面层，该层对气体施加空气动力阻力。这导致VSI的波纹模式终止。仅在上半球和下半球残留有微弱的VSI活动。这些过程发生在典型的尘埃增长时间尺度上，并在几十万年内抑制了强烈的VSI诱导湍流。因此，VSI通常可能仅限于原行星盘的Class I演化阶段。
英文摘要
The Vertical Shear Instability (VSI) is known to create turbulence and strong vertical mixing in protoplanetary disks if thermal relaxation is sufficiently fast. In simulations where this condition is met, VSI can loft dust particles to large altitudes, creating a vertically extended appearance in mock millimeter-wavelength observations, which is inconsistent with the morphology of the majority of observed class II disks. We present simulations of protoplanetary disks with VSI that are consistent with the observed thin-disk geometries, while maintaining the commonly observed bowl-shaped morphology in scattered light images at micrometer wavelength. We show that this outcome arises naturally when the effects of dust coagulation, sedimentation, and dust-gas thermal accommodation are taken into account. Sedimentation-driven coagulation removes large amounts of dust from the disk atmosphere, in the process slowing down the dust-driven cooling of the gas. At the same time, a dense midplane layer of millimeter-sized grains forms, which exerts aerodynamic drag on the gas. This results in the termination of the VSI's corrugation mode. Only weak VSI activity remains in the upper and lower hemispheres. These processes occur on the typical dust growth timescale and suppress strong VSI-induced turbulence within a few hundred thousand years. VSI could thus generally be restricted to the class I evolutionary stages of protoplanetary disks.
Comments20 pages, 12 figures. Published in The Astrophysical Journal Letters
Journal refThomas Pfeil et al 2026 ApJL 1010 L6
