The archaeology of galaxies in the local group

本星系群的考古学

基本信息

批准号：
6379-2011
负责人：
Richer, Harvey
金额：
$ 2.7万
依托单位：
University of British Columbia
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2013
资助国家：
加拿大
起止时间：
2013-01-01 至 2014-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=520915
关键词：
archaeology galaxies local group

项目摘要

Over the past decade I ( and my research team) have been major users of the Hubble Space Telescope. We have been extremely successful in obtaining very large amounts of time (in open competition) to survey a number of ancient star clusters in our Galaxy. The main focus of the research is to determine the ages of these systems and then use that information to glean clues as to when and how our Milky Way Galaxy was formed. We have developed a new age-dating technique that involves measuring precisely the cooling rate of "dead" stars and using this as a clock. Thus far we have explored two clusters in the halo of our Galaxy and have determined that both are about the same age and very old (12 billion years). Since we are quite sure that the Universe itself is only 13.7 billion years old, we now know that our Galaxy (and likely most others) formed rather soon after the Big Bang. We have also applied our chronometer to the disk of our Galaxy which contains its magnificent spiral arms. Here we learned that this Galactic component is significantly younger - by about 4 billion years. Currently we are in the process of obtaining a new set of Hubble data on a star cluster that contains stars similar to those in the central bulge of our Galaxy. An age for this system will provide evidence on whether our Galaxy formed inside out (bulge is older) or from the outside in (bulge is younger).

在过去的十年中，我（和我的研究团队）一直是哈勃太空望远镜的主要用户。我们非常成功地获得了大量时间（在公开竞争中）来调查银河系中的许多古老星团。研究的主要重点是确定这些系统的年龄，然后利用该信息收集有关银河系何时以及如何形成的线索。我们开发了一种新的年龄测定技术，该技术涉及精确测量“死亡”恒星的冷却速率并将其用作时钟。到目前为止，我们已经探索了银河系光晕中的两个星团，并确定它们的年龄大致相同，而且非常古老（120 亿年）。由于我们非常确定宇宙本身只有 137 亿年的历史，因此我们现在知道我们的星系（可能还有大多数其他星系）是在大爆炸后不久形成的。我们还将我们的天文钟应用到了银河系的圆盘上，其中包含着宏伟的旋臂。在这里我们了解到这个银河系成分要年轻得多——大约 40 亿年。目前，我们正在获取一组关于星团的新哈勃数据，该星团包含与银河系中央核球相似的恒星。该系统的年龄将提供证据证明我们的银河系是由内向外（核球较古老）还是由外向内（核球较年轻）形成的。