Young Star Dynamical Mass Ratios Down to and Across the Substellar Boundary

到达和跨越亚恒星边界的年轻恒星动力学质量比

• 批准号: 0406808
• 负责人: Lisa Prato
• 金额: --
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2004-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0406808&HistoricalAwards=false
• 关键词: Young; Star; Dynamical; Mass; Ratios

Having a broad picture of star formation is necessary for understanding both the past and future evolution of our Galaxy. Do star forming regions share global properties, such as initial angular momentum distributions in molecular cloud cores? The frequency, distribution, and properties of young binary stars supply key information. This project is furthering our general understanding of star formation by studying the closest young binary systems in nearby star forming regions. These systems, the spectroscopic binaries, are particularly useful because their radial velocity variations may be measured very precisely and hence their mass ratios and ultimately masses may be accurately determined free of assumptions. The use of high-resolution, infrared spectroscopy for these measurements ensures the identification of even the faintest and lowest mass secondaries in spectroscopic systems. The focus of the proposed projects is on the lower and less well-understood end of the main-sequence. Mass ratio distributions of low-mass spectroscopic binaries will inform us about global characteristics of star formation in different star forming regions. The future determination of absolute masses based on these mass ratios will be crucial for developing accurate models of the formation and evolution of low-mass and substellar objects.Broader impacts: Broad dissemination of results takes the form of publication in refereed journals, press releases, and posters and talks presented at national conferences, enhancing the scientific and technical understanding on the part of the investigator, colleagues, and graduate students. Public access to unique data sets and software applicable to a variety of astrophysical data will be made available on the web.

对于了解银河系的过去和未来的演化，拥有恒星形成的广阔图景是必要的。恒星形成区域是否共享全局属性，例如分子云核心的初始角动量分布？年轻双星的频率、分布和性质提供了关键信息。这个项目通过研究附近恒星形成区域中最近的年轻双星系统，进一步加深了我们对恒星形成的一般理解。这些系统，光谱双星，特别有用，因为它们的径向速度变化可以非常精确地测量，因此它们的质量比和最终质量可以准确地确定，而不需要假设。在这些测量中使用高分辨率红外光谱，确保了光谱系统中即使是最微弱和最低质量的次级物的识别。拟议项目的重点是在主序列的较低和较不容易理解的末端。低质谱双星的质量比分布将告诉我们不同恒星形成区域的恒星形成的整体特征。未来基于这些质量比的绝对质量的确定对于开发低质量和次恒星物体的形成和演化的精确模型至关重要。更广泛的影响：广泛传播的结果以发表在期刊、新闻稿、海报和在国家会议上发表的演讲的形式，提高科研人员、同事和研究生对科学和技术的理解。公众可在网上获得适用于各种天体物理数据的独特数据集和软件。