Astrophysical and Astrochemical Tests of Massive Star Formation Theories

大质量恒星形成理论的天体物理和天体化学测试

• 批准号: 1411527
• 负责人: Jonathan Tan
• 金额: $ 38.87万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1411527&HistoricalAwards=false
• 关键词: Astrophysical; Astrochemical; Tests; Massive; Star

Stars with masses much greater than that of our Sun are the engines that drive the evolution of our galaxy; mixing the interstellar gas and dust with their winds, radiation, and eventually their violent deaths in supernova explosions. This project will improve our understanding of the way in which the most massive of these stars are formed. The project will develop new theoretical and computational models that simulate the formation of these massive stars from their beginnings as condensing core of interstellar hydrogen gas to their birth as the largest stars in our galaxy. These new simulations will include more physically realistic models of the evolution of the proto-stellar core, the surrounding region of rotating infalling matter, and the outflowing winds from the newly forming star. The project will test and verify these models of massive star formation with new observations with state-of-the-art facilities performed at millimeter, sub-millimeter, and mid-infrared wavelengths. The project will use existing Monte Carlo radiative transfer code for turbulent accreting cores, which the PI has modified to include both dust and gas opacities. These models will be used to extend the canonical evolutionary sequence for massive stars to systematically cover a much larger parameter space of initial core mass, core rotation, and environmental factors. The proposers will also incorporate new models for dust grain alignment and the effects of a binary companion to the current radiative transfer computations. The output of the radiative transfer calculations will consist of observables that can be compared with observations by facilities such as the Atacama Large Millimeter/Sub-millimeter Array (ALMA).This project will build upon previous efforts by the PI to train of a new generation of scientists, with a strong emphasis on students from underrepresented groups. The project will communicate its results to the public through the development of a presentation entitled ?Birth of the Giants ? the Most Massive Stars in the Universe? to be shown at local schools and at events organized through the Florida Museum of Natural History.

质量比太阳大得多的恒星是驱动银河系演化的引擎;将星际气体和尘埃与它们的风，辐射混合，最终在超新星爆炸中猛烈死亡。 这个项目将提高我们对这些恒星中最大质量的恒星形成方式的理解。 该项目将开发新的理论和计算模型，模拟这些大质量恒星的形成，从它们开始作为星际氢气的凝聚核心，到它们作为银河系中最大的恒星诞生。 这些新的模拟将包括更真实的原恒星核心演化模型，旋转下落物质的周围区域，以及新形成的星星的外流风。 该项目将测试和验证这些大质量星星形成的模型，并使用最先进的设备在毫米、亚毫米和中红外波长下进行新的观测。 该项目将使用现有的蒙特卡罗辐射传输代码的湍流吸积核心，其中PI已修改，包括灰尘和气体的不透明。 这些模型将用于扩展大质量恒星的典型演化序列，以系统地覆盖初始核心质量，核心旋转和环境因素的更大的参数空间。 提议者还将把尘埃颗粒排列的新模型和双星伴星的影响纳入目前的辐射传输计算。 辐射传输计算的输出将包括可与阿塔卡马大型毫米/亚毫米阵列（阿尔马）等设施的观测结果进行比较的可观测值。该项目将建立在PI之前为培养新一代科学家所做的努力的基础上，重点是来自代表性不足群体的学生。 该项目将通过编写一份题为“如何在全球范围内实现可持续发展”的报告向公众宣传其成果。巨人的诞生？宇宙中最大的恒星将在当地学校和佛罗里达自然历史博物馆组织的活动中展出。