Galaxy, Star, and Planet Formation

星系、恒星和行星的形成

• 批准号: RGPIN-2017-06459
• 负责人: Murray, Norman
• 金额: $ 5.1万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=691527
• 关键词: Galaxy; Star; Planet; Formation

Many people, my self very much included, wonder how the universe, and the galaxies, stars and planets it holds, came about, and how we fit into this larger picture. I propose to study the origin and evolution of galaxy clusters, galaxies, stars, and planets. I am also interested in what astronomical observations can tell us about dark matter, which is believed to hold galaxies and galaxy clusters together, and about dark energy, which is believed to be pushing galaxies away from each other, i.e., accelerating the expansion of spacetime.*** In work carried out over the last five years, I and my coworkers have proposed that most planets form in place, in dust and rock rich disks around young stars. Roughly half of these closely packed planetary systems are stable for eons, while the rest of the systems were unstable, and appear as single transiting planets. I aim to identify the mechanism leading to the instability; if I succeed, we will learn more about the initial conditions for planet formation.*** Over the same time period I have worked extensively on earlier stages, when the stars themselves acquired most of their mass. It is known that most stars, including our own Sun, form in star clusters. My work has shown that the total stellar mass in a cluster grows in proportion to the square of the time; individual stars grow in mass more nearly in direct proportion to the time. My group will carry out simulations to see how the fuel for star formation is depleted, and how the proto-stellar disk mass evolves in time.*** Moving up in scale, I will continue work on galaxy formation. I have been involved in a collaboration using simulations to model galaxies starting from small fluctuations in density soon after the big bang up to fully formed objects today. We have successfully predicted the stellar masses of galaxies in dark matter halos with a large range of masses; we were the first group able to do so. The next step is to test the model galaxies extensively, for example by comparing the amount of gas in the regions around the simulated galaxies to that seen in observations of both nearby and distant galaxies. *** On yet larger scales, I am leading the Canadian consortium that is one of the major partners in the effort to build CCAT Prime, a six meter telescope that will be used to map the distribution of matter on large scales. CCAT Prime will be ideal for Stage IV Cosmic Microwave Background work, the next generation effort to measure the fundamental parameters of the Universe. In support of this effort, I will undertake, using the galaxy simulations just mentioned, forecast efforts to help with the design of the telescope.

很多人，包括我自己，都想知道宇宙、星系、恒星和行星是如何形成的，以及我们是如何融入这个更大的图景的。我建议研究星系团、星系、恒星和行星的起源和演化。我也对天文观测能告诉我们的暗物质和暗能量感兴趣，暗物质被认为是将星系和星系团聚集在一起的物质，暗能量被认为是推动星系相互远离的物质，也就是说，加速了时空的膨胀。在过去五年的工作中，我和我的同事们提出，大多数行星都是在年轻恒星周围富含尘埃和岩石的圆盘上形成的。这些紧密排列的行星系统中大约有一半是稳定的，而其余的系统则不稳定，并且表现为单一的凌日行星。我的目标是找出导致不稳定的机制；如果我成功了，我们将更多地了解行星形成的初始条件。在同一时期，我对早期阶段进行了广泛的研究，那时恒星本身获得了大部分质量。众所周知，大多数恒星，包括我们的太阳，都是在星团中形成的。我的工作表明，一个星团中恒星的总质量与时间的平方成比例增长；单个恒星的质量增长几乎与时间成正比。我的小组将进行模拟，看看恒星形成的燃料是如何耗尽的，以及原始恒星盘的质量是如何随时间演变的。在规模上，我将继续研究星系的形成。我参与了一个合作项目，利用模拟技术对星系进行建模，从大爆炸后不久密度的微小波动到今天完全形成的物体。我们已经成功地预测了大范围暗物质晕中星系的恒星质量；我们是第一批能够做到这一点的人。下一步是对模型星系进行广泛的测试，例如，将模拟星系周围区域的气体量与观测到的近星系和远星系的气体量进行比较。***在更大的尺度上，我正在领导一个加拿大财团，它是建造CCAT Prime的主要合作伙伴之一，这是一个6米长的望远镜，将用于绘制大尺度上的物质分布。CCAT Prime将是第四阶段宇宙微波背景工作的理想选择，这是下一代测量宇宙基本参数的努力。为了支持这项工作，我将利用刚才提到的星系模拟，进行预测工作，以帮助设计望远镜。