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

这项EAGER奖资助了一项合作研究，研究将在恒星周围形成行星的物质中的气体和尘埃的湍流。要研究的机制可能对形成未来行星核心的小岩石体很重要，而它们的形成过程却知之甚少。这项研究对了解我们自己的太阳系和其他恒星周围行星的形成有潜在的影响。该研究将建立一个由本科生、研究生和博士后学者组成的团队。我们研究的合作性质将协同为旧金山州立大学（一个少数族裔服务的非博士机构）的学生提供与加州大学伯克利分校的学生和教师合作的机会。研究人员还将培训和指导一名博士后研究员。为了实现他们的科学目标，该团队将计算充满大振幅湍流的原行星盘（PPD）死区内的角动量传输，计算尘埃和岩石在湍流PPD中积聚和聚集的速率，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，其成分是否与观测相符。他们还将开发执行上述动量输运计算的能力，通过扩展他们目前的频谱代码，该代码适用于非弹性流，以适用于马赫数小于3的完全可压缩流（如死区）。该团队将通过将岩石和尘埃模拟为流体流动的不同阶段来取代他们的“粒子跟踪”代码，从而开发有效地执行上述小行星和球粒形成计算的能力。

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.