Collaborative Research: Stars from Clouds - Turbulence, Magnetic Fields and Dynamics of Forming Star Clusters

恒星是在星系中的气体分子云中形成的。天文学家试图了解是什么导致分子云的特定区域形成恒星。这个看似简单的问题是现代天体物理学几个基础研究前沿的核心，包括星系的形成和星团的起源。研究人员计划对磁化分子云进行数值模拟，其中包括重要的物理过程和各种初始条件。研究人员将把他们的模型与来自美国国家科学基金会阿塔卡马大型毫米/亚毫米阵列（ALMA）的巨分子云（gmc）的无线电波长观测结果进行比较。在他们对gmc结构和运动学的研究中，他们将把重点放在已经在银道面发现的长丝状云上。研究人员将使用正在进行的对数千颗年轻恒星的光学调查数据来测试年轻恒星系统的动力学模型。研究人员将培训本科生和研究生先进的研究方法，这将对他们未来在科学或工业领域的职业生涯有普遍的好处。调查人员计划为公众宣传项目举办一场新的“云中之星”演讲。该团队计划对磁化分子云的动力学进行数值模拟，包括从更大规模的剪切星系盘模拟中提取的云、巨大的分子云碰撞和理想的周期性盒状湍流。模拟的一个重点是在自适应网格细化模拟中包含非理想的双极磁流体动力学过程和重联扩散，这也可以模拟天体化学并预测与观测相比较的指标。对于恒星核心，重点将是研究前恒星和原恒星核心的空间分布和数量。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Stars are formed in molecular clouds of gas in galaxies. Astronomers seek to understand what causes a particular region of a molecular cloud to form a star. This seemingly simple question is at the heart of several basic research frontiers of modern astrophysics, including galaxy formation and the origin of stellar clusters. The investigators plan numerical simulations of magnetized molecular clouds that include important physical processes and a variety of initial conditions. The investigators will compare their models to radio wavelength observations of Giant Molecular Clouds (GMCs) from NSF’s Atacama Large Millimeter/submillimeter Array (ALMA). In their studies of the structure and kinematics of GMCs, they will focus on long, filamentary clouds that have been found in the Galactic plane. The investigators will test models of dynamics of young stellar systems using data from ongoing optical surveys of thousands of young stars. The investigators will train undergraduate and graduate students in advanced research methods, which will be of general benefit in their future careers in either science or industry. The investigators plan a new “Stars from the Clouds” presentation for public outreach programs.The team plans numerical simulations of the dynamics of magnetized molecular clouds, including clouds extracted from larger scale shearing galactic disk simulations, giant molecular cloud collisions and idealized periodic box turbulence. A focus of the simulations is inclusion of non-ideal magneto-hydrodynamic processes of ambipolar and reconnection diffusion in adaptive mesh refinement simulations, which also model astrochemistry and predict metrics to be compared to observations. For the stellar cores, the priority will be study of spatial distributions and populations of pre-stellar and proto-stellar cores.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.