Galactic History- Old Stellar Populations in Edge-on Disk Galaxies

9624542莫里森研究星系中古老恒星群的能力，其结果可能被用来追踪星系的形成和演化，这在几个方面得益于大尺寸电荷耦合器件(CCD)的出现和计算能力的增强。一项重大的进步是利用星系的深度CCD成像技术的发展，这使得人们能够以前所未有的细节研究附近星系的古老恒星群。将要进行的观测将达到比之前的观测弱2级以上。这项研究的结果将有助于利用最近开发的技术来描绘附近具有代表性的盘状星系样本中较老的恒星群。将对附近10个哈勃星系的性质进行系统研究，这些星系的哈勃类型从Sc到Sa到S0不等。在这项工作中特别感兴趣的是这些星系的厚盘和恒星晕的性质，如果它们存在的话。对样本中观察到的厚盘的研究将使人们能够检验目前流行的厚盘星系通过卫星吸积形成的模型。如果模型成功地预测了这个样本的厚盘性质，那么厚盘就有可能被用作星系吸积历史的示踪剂。这个样本中厚盘和光晕的特征将使我们能够第一次测试银河系中古老的恒星群是否是附近盘星系的典型。大多数观测将在凯斯西部储备大学(CWRU)位于基特峰纳塔尔天文台(KPNO)的Burrell Schmidt望远镜上进行，CWRU可以特别进入该望远镜。将为施密特购买一个改进的CCD系统，量子效率提高5倍。Ccd系统的这一升级将能够在光谱的蓝色区域进行表面光度观测，从而提供关于厚盘和晕星群的颜色(因此是Ge和金属丰度)信息。教学发展活动将包括本科生参与“专业天文学入门”课程的研究和课程开发。这将使用主题方法将教授的内容与当前的研究紧密联系在一起。当前天文学研究的两个主要领域，太阳系是如何形成的，以及宇宙距离尺度问题的价值的确定，将在为期两个学期的课程中作为反复出现的主题。其他与教学有关的活动将包括通过CWRU新的教学中心组织的几种改进教学的创新方法(包括主动学习技术和大力使用万维网)。将实施一项计划，允许本科生陪同PI到KPNO进行观察旅行。***

9624542 Morrison The ability to study old stellar populations in galaxies, the results of which may be used to trace the formation and evolution of galaxies, has benefited in several ways from the advent of large-format Charge-Coupled-Devices (CCDs) and increased computing power. A major advance has been the development of techniques of using deep CCD imaging of galaxies, which allows one to study the old stellar populations of nearby galaxies in unprecedented detail. The observations to be carried out will reach more than 2 magnitudes fainter than previous observations. The results of the research will serve to delineate the older stellar populations of a representative sample of nearby disk galaxies, using recently developed techniques. A systematic investigation of the properties of 10 nearby edge-on disk galaxies with Hubble types ranging from Sc though Sa to S0 will be carried out. Of particular interest in this work are the properties of thick disks and stellar halos of these galaxies, when they exist. The study of the thick disks observed in the sample will able one to test the currently popular models of thick disk galaxy formation by satellite accretion. If the models predict successfully the thick disk properties of this sample, there is the possibility of using thick disks as tracers of the accretion history of galaxies. The characterization of thick disks and halos in this sample will allow us to test for the first time whether the Milky Way's old stellar populations are typical of nearby disk galaxies. Most of the observations will be taken on Case Western Reserve University's (CWRU) Burrell Schmidt telescope at Kitt Peak Natal Observatory (KPNO), to which CWRU has special access. An improved CCD system for the Schmidt, with a factor of 5 improvement in quantum efficiency, will be purchased. This upgrade of the CCD system will enable surface photometry observations in the blue region of the spectrum, and thus provide color (and hence a ge and metallicity) information on the thick disk and halo stellar populations. Teaching development activities will include involvement of undergraduate students in research and in course development of the "Introduction to Astronomy for Majors" course. This will closely tie what is taught to current research, using a thematic approach. Two major areas of current astronomical research, how the solar system was formed and the determination of the value of cosmic distance scale problem, will be used as recurring themes in the two-semester course. Other teaching-related activities will include several innovative ways of improving teaching, organized through CWRU's new teaching center (including active learning techniques and a strong use of the World Wide Web). A program to allow undergraduates to accompany the PI on observing trips to KPNO will be carried out. ***