Old Stellar Populations at High Redshifts

高红移的老恒星族群

• 批准号: 0307335
• 负责人: Alan Stockton
• 金额: --
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307335&HistoricalAwards=false
• 关键词: Old; Stellar; Populations; Redshifts

AST-0307335StocktonSemi-analytic models based on the standard cold dark matter (CDM) theory suggest that most elliptical galaxies formed between redshifts one and two, with the most massive forming most recently. However, there are observations which sit uneasily with this picture. Although some questions can be addressed by careful and detailed examination of local ellipticals, it is nevertheless crucial to have observations of galaxies at high redshifts with populations of stars that were already old at the epoch corresponding to those redshifts (simply called 'old galaxies'). The centerpiece of this project is acquiring images of a significant and representative sample of old galaxies at redshifts between 1.5 and 2.5, and possibly also in the range 3:4 to 3:8, using adaptive optics (AO) on 8-m-class telescopes to deliver resolutions three to four times better than can be obtained with the Hubble Space Telescope. Emphasis is on infra-red imaging, starting with fields for which deep optical data already exist, to yield volume density, clustering properties, and the distribution of morphologies. Identifying and determining physical properties for the most luminous old galaxies over a range of redshifts will place new constraints on theories of their formation and early evolution.Integrated into this proposal are procedures to ensure wide and timely dissemination of the results, both within the scientific community and to interested lay audiences, and the project will provide material for both undergraduate teaching and general public outreach.***

AST-0307335Stockton 基于标准冷暗物质 (CDM) 理论的半解析模型表明，大多数椭圆星系在红移一到二之间形成，其中质量最大的星系是最近形成的。 然而，有一些观察结果与这张图片不一致。 虽然一些问题可以通过对局部椭圆星系进行仔细和详细的检查来解决，但对高红移星系进行观测仍然至关重要，其中的恒星群在与这些红移相对应的时代已经很老了（简称为“老星系”） 。 该项目的核心是使用 8 米级的自适应光学器件 (AO) 获取红移在 1.5 到 2.5 之间（也可能在 3:4 到 3:8 范围内）的重要且具有代表性的旧星系样本的图像望远镜提供的分辨率比哈勃太空望远镜高三到四倍。 重点是红外成像，从已经存在深层光学数据的领域开始，以产生体积密度、聚类特性和形态分布。 识别和确定最明亮的古老星系在一系列红移范围内的物理特性将对其形成和早期演化的理论施加新的限制。该提案中纳入了确保结果在科学界内广泛而及时传播的程序以及感兴趣的外行观众，该项目将为本科生教学和公众宣传提供材料。***