Modeling the Formation of Disks of Gas and Dust Around Young Stars

这个天文学项目将使用计算机模型来了解年轻恒星周围的气体和尘埃盘是如何形成的。正是这些圆盘形成了行星，比如地球和太阳系中的其他行星。现在有强有力的证据表明，我们银河系中的大多数（如果不是全部的话）恒星都有自己的行星系统。弗吉尼亚大学的研究小组将使用他们已经研究多年的复杂计算机代码来研究这一过程。他们将在他们的模型中包括“磁场”和“湍流”的影响。两者都被认为是太空中的重要过程，尤其是在我们所知的恒星之间的大云团中。这些云在自身重量的作用下坍缩，形成恒星和行星。一名研究生和一名本科生将参与这个项目。研究人员将制作圆盘形成的动画电影，用于非科学专业的大型天文学入门课程，并将为移动天文馆开发活动，作为“黑暗的天空，聪明的孩子”计划的一部分，这是一项针对弗吉尼亚州阿尔伯马尔县农村小学生的科学教育活动。恒星形成的核心被观察到明显磁化，磁制动已被证明能够抑制盘的形成，导致所谓的磁制动灾难。该计划的目标是确定避免灾难的两个主要候选者，非理想磁流体动力学（MHD）效应和湍流，是否可以使行星形成盘在现实磁场的存在下形成，以及这些盘是否满足最近ALMA观测设定的日益严格的观测约束。提议者将使用并进一步开发一个经过良好测试的MHD代码，称为ZeusTW。在项目的第二部分，他们将使用ENZO自适应网格细化MHD代码来合成孤立核心和集群中的磁盘形成。

This astronomy project will use computer models to understand how disks of gas and dust form around very young stars. It is from these disks that planets, like Earth and the other planets in our Solar System, are formed. There is now strong evidence that most, if not all, stars in our Galaxy have their own system of planets. The team at the University of Virginia will use sophisticated computer code that they have been working with for many years to study this process. They will include the effects of "magnetic fields" and "turbulence" in their models. Both are thought to be important processes in space, especially in the large clouds that we know lie between the stars. These clouds collapse under their own weight to form stars and planets. A graduate and an undergraduate student will be involved in this project. The investigators will produce animated movies of disk formation for use in large introductory astronomy classes for non-science majors and will develop activities for a mobile planetarium as part of the "Dark Skies, Bright Kids" program, a science educational activity that targets elementary school students in rural Albemarle County, Virginia.Star-forming cores are observed to be significantly magnetized and magnetic braking has been shown to be capable of suppressing disk formation, leading to the so-called magnetic braking catastrophe. The goal of the proposed program is to determine whether the two leading candidates for averting the catastrophe, non-ideal magnetohydrodynamic (MHD) effects and turbulence, can allow the planet-forming disks to form in the presence of a realistic magnetic field, and whether such disks satisfy the increasingly tight observational constraints set by recent ALMA observations. The proposers will use and further develop a well-tested MHD code known as ZeusTW. In the second part of the project they will use the ENZO adaptive mesh refinement MHD code to synthesize disk formation in isolated cores and in clusters.