CDI-Type I: Combined Global Physical, Chemical, and Mineralogical Models of Protoplanetary Disks

CDI-I 型：原行星盘的全球物理、化学和矿物学组合模型

• 批准号: 0835734
• 负责人: Mordecai-Mark Mac Low
• 金额: $ 57.52万
• 依托单位: American Museum Natural History
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0835734&HistoricalAwards=false
• 关键词: CDI; Type; Combined; Global; Physical

The Earth is unique among known planets in having liquid water on its surface, a crucial reason for the existence of life. Explaining how this came to be, and predicting conditions friendly to life elsewhere requires understanding the protoplanetary disk from which Earth and the other planets formed, a complex, interacting system of rocks, dust, gas, plasma, and magnetic fields in orbit around the young Sun. Many models by different scientific communities have addressed separate aspects of this problem, but none has integrated all the different physical, chemical, and mineralogical processes into a single, general, continuously improvable, three-dimensional, computational model.Our imminent entry into the petascale computing era makes such a model practical for the first time. This project will be the first serious attempt to develop a complete, multi-physics model based on a global simulation of a protoplanetary disk. We will include three major physical processes. First is the turbulence driven by magnetic fields coupled to the partially ionized gas, which determines how fast the disk accretes onto the star and how well dust can stick together to form the building blocks of planets. Second is the radiative cooling of the disk, which determines the temperature of the disk, and is determined by how dusty the disk is. That, in turn, is controlled partly by the temperature. Third, the gas chemistry and the temperature, as well as the dust properties, determine the ionization of the gas, which in turn determines how turbulent the disk is. All of these processes will be included in a common computational framework. This framework will rely on a novel numerical algorithm for computing magnetized gas flows using simulated particles moving with the gas. This algorithm combines advantages and evades limitations of both traditional grid-based simulation codes and of more widely used particle methods such as smoothed particle hydrodynamics. Our team includes the inventor of this method.With a new, integrated model, we will be able to better understand Earth's position and properties, the properties of other Solar System objects, and observations of extrasolar planetary systems.The funding for this project will support the interdisciplinary training of a graduate student in the areas of meteoritics and astrophysics treated here. A collaboration between the host institution and two European institutions will be supported, with graduate students traveling in both directions for collaboration and training. Three undergraduate students will also participate in this research.The research undertaken here will inform the exhibitions and education work of the PI and co-PI Ebel. Currently, their projects include a new Hayden Planetarium Space Show (estimated international viewership 7 million over 5 years, including 0.5 million NYC school children), a photo exhibit on the Cassini-Huygens mission to Saturn, as well as extensive work with the professional development and community education departments of the Museum, and mentoring summer REU students and interns.

地球在已知的行星中是独一无二的，在其表面上有液态水，这是生命存在的至关重要原因。 解释这是如何产生的，并预测对其他地方生活的友好条件，需要了解地球和其他行星形成的原星盘，这是一个复杂的，相互作用的岩石，尘埃，灰尘，气体，等离子体和磁场，围绕年轻太阳的轨道。 不同科学社区的许多模型都解决了这个问题的各个方面，但是没有一个将所有不同的物理，化学和矿物学过程整合到一个单一的，一般，不断改进的，三维计算模型中。我们即将进入Petascale Computing Era，这使得第一次实用了这种模型。 该项目将是基于原动性磁盘的全球模拟开发完整的多物理模型的首次认真尝试。 我们将包括三个主要的物理过程。 首先是由磁场驱动的湍流，该磁场耦合到部分电离气体，该磁场决定了磁盘积聚到恒星上的速度，以及灰尘如何粘在一起形成行星的组成部分。 其次是磁盘的辐射冷却，它决定了磁盘的温度，并取决于磁盘的尘土飞扬。 反过来，这部分由温度控制。 第三，气体化学和温度以及灰尘特性决定了气体的电离，这又决定了磁盘的湍流程度。所有这些过程都将包含在一个通用的计算框架中。 该框架将依靠一种新型的数值算法来使用与气体移动的模拟颗粒计算磁化气流。该算法结合了优势并逃避了传统基于网格的仿真代码和更广泛使用的粒子方法（例如平滑粒子流体动力学）的局限性。我们的团队包括这种方法的发明者。使用新的集成模型，我们将能够更好地了解地球的位置和特性，其他太阳系对象的特性以及对外行星外行星系统的观察。该项目的资金将支持该项目的跨学科培训，在此处提供的众多学生和天文学领域的研究生培训。 将支持主持机构与两个欧洲机构之间的合作，研究生朝着两个方向旅行进行协作和培训。三名本科生也将参加这项研究。这里进行的研究将为PI和Co-Pi Ebel的展览和教育工作提供信息。 目前，他们的项目包括一场新的海顿天文馆太空展览（估计5年内国际收视率700万，包括50万纽约市的儿童），在卡西尼 - 赫林格斯（Cassini-Huygens）的土星任务上进行的摄影展览，以及与博物馆的专业发展和社区教育部门的广泛合作，以及指导的夏季雷乌（Summer Reu）学生和实习生。