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，都想知道宇宙和它所包含的星系、恒星和行星是如何产生的，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。我还对天文观测能告诉我们什么关于暗物质和暗能量感兴趣，暗物质被认为将星系和星系团聚集在一起，暗能量被认为正在推动星系相互远离，即加速时空的扩张。*在过去五年开展的工作中，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中形成的。这些紧密堆积的行星系统中，大约有一半在亿万年内是稳定的，而其余的系统是不稳定的，看起来像是单一的凌日行星。我的目标是确定导致不稳定的机制；如果我成功了，我们将了解更多关于行星形成的初始条件。*在同一时间段，我在早期阶段进行了广泛的工作，当时恒星本身获得了大部分质量。众所周知，大多数恒星，包括我们自己的太阳，都是在星团中形成的。我的工作表明，星团中的恒星总质量与时间的平方成正比增长；单个恒星的质量增长更接近与时间成正比。我的团队将进行模拟，以了解恒星形成的燃料是如何耗尽的，以及原恒星盘质量是如何随时间演变的。*随着规模的扩大，我将继续研究星系形成。我参与了一项合作，使用模拟对星系进行建模，从大爆炸后不久的密度小波动到今天的完全形成的天体。我们已经成功地预测了具有大质量范围的暗物质晕中星系的恒星质量；我们是第一个能够做到这一点的小组。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对近星系和远星系的观测结果进行比较。*在更大的尺度上，我正在领导加拿大财团，该财团是建造CCAT Prime的主要合作伙伴之一，CCAT Prime是一个6米长的望远镜，将用于绘制大尺度上的物质分布图。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。为了支持这一努力，我将利用刚才提到的星系模拟进行预测，以帮助设计望远镜。