Collaborative EAGER Proposal: The Dead Zones of Protoplanetary Disks are Not Dead - How Turbulence Transports Angular Momentum and Forms Planetesimals

这一热切的奖项资助了一项合作研究，以研究气体和尘埃在将形成恒星周围行星的物质中的湍流。要研究的机制可能对形成小型岩石体很重要，这些岩石体是未来行星的核心，其形成过程尚不清楚。这项研究对理解我们自己太阳系的形成以及其他恒星周围行星的形成具有潜在的影响。这项研究将建立一支由本科生和研究生以及博士后学者组成的团队。我们研究的协作性质将协同为旧金山州立大学的学生提供与加州大学伯克利分校的学生和教职员工合作的机会。旧金山州立大学是一家面向少数族裔的非博士生机构。研究人员还将培训和指导一名博士后研究人员。为了实现他们的科学目标，该团队将计算充满大范围湍流的原行星盘(PPD)死区中的角动量传输，计算尘埃和岩石在湍流PPD中积累和聚集的速率，并计算PPD中的混合。特别是，他们将确定形成球粒的成分是否充分混合，其组成与观察结果一致。他们还将开发有效地执行上述动量输运计算的能力，方法是将他们目前适用于滞弹性流动的频谱代码扩展到适用于马赫数小于3的完全可压缩流动(如在死区)。该团队将开发出有效执行上面列出的行星小行星和球粒形成计算的能力，方法是用一种将岩石和尘埃模拟为流体流动的不同阶段的代码来取代他们的“粒子跟踪”代码。

This EAGER award funds a collaborative study to study the turbulence of gas and dust in the material that will form planets around stars. The mechanism to be studied could be important in forming the small rocky bodies that are the cores of future planets, and whose process of formation is poorly understood. This study has potential impact in understanding the formation of our own Solar System and of the planets around other stars. The research will create a team consisting of undergraduate and graduate students, and postdoctoral scholars. The collaborative nature of our research will synergistically provide opportunities for students at San Francisco State University, a minority-serving non-PHD institution, to work with students and faculty at University of California at Berkeley. The investigators will also train and mentor a postdoctoral researcher.To accomplish their science goals, the team will compute angular momentum transport in a protoplanetary disk (PPD) dead zone filled with large-amplitude turbulence, compute the rate at which dust and rocks accumulate and agglomerate in a turbulent PPD, and compute mixing in a PPD. In particular, they will determine if the ingredients from which chondrules form become sufficiently mixed that their composition agrees with observations. They will also develop the capability to carry out the above-listed calculation of momentum transport efficiently by extending their current spectral code, which works with anelastic flows, to one that works with fully-compressible flows with Mach numbers less than 3 (as in dead zones). The team will develop the capability to carry out the above-listed calculations of planetesimal and chondrule formation efficiently by replacing their "particle-tracking" code with one that models the rocks and dust as different phases of the fluid flow.