CAREER: Investigating the Sources of the X-ray Background with Chandra and the Hobby-Eberly Telescope

钱德拉卫星、XMM卫星和大型光学望远镜数据的结合，将彻底改变对河外x射线背景的调查。研究将在现有数据革命的最前沿进行，这些数据将揭示产生大部分x射线背景的来源的性质和演变。这项研究工作将利用宾夕法尼亚州立大学的两个基础项目：钱德拉上的ACIS CCD相机和8米级的霍比-埃伯利望远镜（30%由宾夕法尼亚州立大学拥有）。在发射后不久，钱德拉将对哈勃深空及其周围的天空区域进行长时间（237公里）的观测。这次观测是宾夕法尼亚州立大学保证时间计划的一部分，它将探测2-10 keV的宇宙，比以往任何时候都要深30倍。计划中的观测将使利用霍比-埃伯利望远镜和公开的多波长数据识别和研究约150-200个探测到的x射线源成为可能。霍比-埃伯利望远镜是这个项目的理想仪器，因为它是排队安排的，是为光谱调查工作量身定制的。具体的科学目标是：(1)发现产生2-10 keV x射线背景的源的性质；(2)确定哈勃深场区活动星系的含量；(3)研究QSO x射线光谱形状和变率与红移的关系；(4)进行相互关联分析，以研究过于微弱而无法单独检测到的x射线源。这项深度调查工作将通过使用专有的和存档的钱德拉和XMM数据，对大约半平方度的天空进行中等深度的调查来扩展。这项中等深度的调查将利用霍比-埃伯利望远镜的力量，这些数据将用于了解活动星系在宇宙大部分时间内的x射线演化。特别是，这些数据将用于调查最近声称的QSO密度演变。将成立一个研究小组，作为一项活动，向学生传授自己进行天文发现所需的技能。该小组将包括一些优秀的宾夕法尼亚州立大学本科生在研究项目。学生将专注于定义明确的项目，如多波长源匹配和变异性研究。他们的实践经验将帮助他们在教师主导的学习和自我驱动的研究活动之间做出关键的转变。此外，宾夕法尼亚初级科学院（PJAS）将努力增加天文学的研究。每年约有6500名来自宾夕法尼亚州各地的初高中学生参加PJAS研究奖竞赛。然而，目前很少有学生选择从事天文学项目，因为他们不知道合适的研究主题或可供他们使用的天文学资源。此外，PJAS目前没有提供专门的天文学奖项。PJAS的学生和导师将通过直接交流和访问专门的全球网站来帮助他们进行合适的天文学研究项目。PJAS天文奖将为7-8年级和9-12年级的学生设立。通过评审PJAS天文项目以及与学生和老师讨论项目所获得的信息将用于了解PJAS学生和导师的需求。与参加宾夕法尼亚州立天文学在职研讨会（PSIWA）的初中和高中教师的讨论表明了对PJAS天文学项目的浓厚兴趣，PSIWA将作为催化PJAS天文学推广计划的工具

AST-9983783Brandt Surveys of the extragalactic X-ray background are about to be revolutionized by the combi-nation of the data from the satellites Chandra, XMM, and large optical telescopes. Research will be carried out at the forefront of this revolution in available data that will reveal the nature and evolution of the sources that create the bulk of the X-ray background. This research effort will exploit two of Pennsylvania State's cornerstone projects: the ACIS CCD camera on Chandra and the 8-m class Hobby-Eberly Telescope (30% owned by Penn State). Shortly after its launch, Chandra will make a long (237 ks) observation of the Hubble Deep Field and the area of sky surrounding it. This observation is part of the Pennsylvania State guaranteed time program, and it will probe the 2-10 keV Universe ~30 times deeper than ever before. The planned observations will make it possible to identify and study the ~150-200 detected X-ray sources using the Hobby-Eberly Telescope and publicly available multiwavelength data. The Hobby-Eberly Telescope is the ideal instrument for this project since it is queue scheduled and tailored for spectroscopic survey work. The specific science goals are (1) to discover the nature of the sources that create the 2-10 keV X-ray background; (2) to determine the active galaxy content of the Hubble Deep Field area; (3) to examine the dependence of QSO X-ray spectral shapes and variability on redshift; and (4) to perform cross-correlation analyses to study X-ray sources that are too faint to be individ-ually detected. This deep survey work will be extended by a moderate-depth survey over ~ one-half square degrees of sky using proprietary and archival Chandra and XMM data. This moderate-depth survey will exploit the power of the Hobby-Eberly Telescope, and the data will be used to understand the X-ray evolution of active galaxies over most of the age of the Universe. In particular, the data will be used to investigate recent claims of QSO density evolution.A research group will be built up that will have as an activity the teaching to students the skills needed to make their own astronomical discoveries. The group will include some of our superb Pennsylvania State undergraduate students in the research projects. The students will concentrate on well-defined projects such as multiwavelength source matching and variability studies. Their hands-on experiences willhelp them make the critical transition between teacher-led learning and self-driven research activities.Furthermore, there will be efforts to increase the study of astronomy in the Pennsylvania Junior Academyof Science (PJAS). Each year ~6500 junior and senior high-school students from acrossPennsylvania participate in a PJAS research award competition. However, at present few studentschoose to pursue astronomy projects because they are not aware of the appropriate researchtopics or the astronomy resources available to them. In addition, no dedicated astronomyawards are presently offered by the PJAS. The PJAS students and supervisors will be given help to pursuesuitable astronomy research projects via both direct communication and access to a dedicated WorldWide Web site. PJAS astronomy awards will be established for students in grades 7-8and 9-12. The information obtained by judging PJAS astronomy projects and discussing the projects with the students and teachers will be used to remain aware of the needs of PJAS students and supervisors. Discussions with junior and senior high-school teachers attending the Pennsylvania State Inservice Workshops in Astronomy (PSIWA) have indicated a strong interest in PJAS astronomy projects, and the PSIWA will be used as a vehicle to catalyze the PJAS astronomy outreach program.***