CAREER The Digital Sky: Bringing Cosmology into the Classroom

越来越明显的是，下一个十年将标志着观测宇宙学黄金时代的开始。技术的进步使绘制星系在本地和遥远宇宙中的属性和分布成为可能，绘制出前所未有的细节。新的天文测量正在进行中，或即将完成，它将为数亿个天体制作图像和光谱，测量范围涵盖整个电磁频谱(从X射线波长到无线电频率)。在不久的将来，我们将不再局限于在国家或私人设施申请望远镜时间。取而代之的是，人们将能够“拨打”天空的某个区域(虚拟天文台正在成为现实)。这一新的研究范式将对本科生、研究生和博士后层面的研究产生深远的影响。这些新的多频率观测需要解决的一个基本问题是，星系是如何作为红移或回顾时间的函数而演化的。现有的光度和光谱测量为这一演化提供了一个框架，发现总的恒星形成率从红移z=0迅速增加到红移z=1(光度增加10倍)。这些调查的局限性在于，它们覆盖了天空中非常小的区域(例如，有史以来拍摄的最深的图像，哈勃深场，一侧只有2角分钟的深度)，并且只包含数百个星系。因此，我们没有足够的星系数量来识别星系演化的大致特征(即我们的分析受到散粒噪声的限制)，也没有足够的体积来测量我们是否看到了宇宙演化的真实反映(即我们的样本方差有限)。这些问题中的许多问题将通过新的多色天文测量来解决。仅斯隆数字巡天计划就将包含108个星系，覆盖了大量的天空。这将是第一次有机会获得大量的、统计上完整的星系样本，这些样本可以提供对本地和遥远宇宙的准确普查。通过使用新的统计技术，我们可以利用这些调查中的多色信息来估计星系的物理性质(即它们的红移、光谱类型和光度)。由此，我们可以直接追踪星系如何随红移、星系类型和环境的变化而变化，从而指导星系形成和演化的理论。除了对星系形成和演化的物理学的洞察外，这些数据将为介绍学生进入天体物理科学开辟新的途径。这些多频率观测可以组合在一起形成一个数字天空；一个覆盖了大部分夜空的恒星和星系数据库，本科生和研究生都可以访问。从本质上讲，学生们将可以使用他们自己的望远镜，并可以按照自己的速度探索或分析数据。鉴于这些新的天空测量具有巨大的研究和教学潜力，匹兹堡大学将实施一项旨在建立研究生和本科生天体物理学课程的研究和教育计划。这些计划的主要目标是：o量化星系的性质(它们的光谱类型、恒星形成和光度)是如何从z=0的红移演化到z=i的，并确定是什么物理过程驱动了这些变化。o追踪低红移和中等红移(Z1)的星系团作为回顾时间、星系类型和环境的函数，并将这些观测与目前的星系形成和演化的宇宙学理论联系起来。o将新的虚拟天文台发展成本科生和研究生的研究和教学环境(“虚拟望远镜”)。O将计算科学与天体物理学相结合，使研究生和本科生能够相互交流思想和技术。该项目由天文科学系资助。

AST-9984924CONNOLLYIt is becoming increasingly apparent that the next decade will mark the beginning of a golden age for observational cosmology. Technological advances have now made it feasible to map the properties and distributions of galaxies in the local and distant Universe with unprecedented detail. New astronomical surveys are underway, or nearing completion, that will produce images and spectroscopy for hundreds of millions of objects each with measurements covering the full electromagnetic spectrum (from X-ray wavelengths through to radio frequencies). In the near future we will no longer be restricted to applying for telescope time at national or private facilities. Instead, people will be able to "dial-up" a region of the sky (a virtual observatory is becoming a reality). This new paradigm for undertaking research will have profound implications for research at the undergraduate, graduate and postdoctoral levels. One of the fundamental questions to be addressed with these new multi-frequency surveys is how do galaxies evolve as a function of redshift or lookback time. Extant photometric and spectroscopic surveys provide a framework for this evolution, finding a rapid increase in the total star formation rate from a redshift of z = 0 to redshift z = 1 (a factor of 10 increase in luminosity). The limitation of these surveys is that they extend over very small regions of the sky (for instance the deepest image ever undertaken, the Hubble Deep Field, subtends only 2 arcminutes on a side) and comprise only a few hundred galaxies. Consequently, we do not have the numbers of galaxies to identify anything more than the broad features of galaxy evolution (i.e. our analyses are shot noise limited) nor do we survey sufficient volume to be able to say whether we are seeing a true reflection of how the Universe evolves (i.e. we are sample variance limited).Many of these issues will be resolved by the new multicolor sky surveys. The Sloan Digital Sky Survey alone will contain 108 galaxies and cover a huge volume of the sky. For the first time, there will be access to large, statistically complete samples of galaxies that can provide an accurate census of the local and distant Universe. Through the use of novel statistical techniques we can use the multicolor information within these surveys to estimate the physical properties of galaxies (i.e. their redshifts, spectral types and luminosities). From this we can then directly trace how galaxies change as a function of redshift, galaxy type and environment and thereby guide the theories of galaxy formation and evolution.Beyond the insights into the physics of galaxy formation and evolution, these data will open new avenues for introducing students into the astrophysical sciences. These multifrequency surveys can be combined to form a digital sky; a database of stars and galaxies covering a large fraction of the night sky that is accessible to undergraduate and graduate students alike. Students will, in essence, have access to their own telescope and can explore or analyze the data at their own pace. Given the enormous research and teaching potential of these new sky surveys, a program of research and education designed to build the graduate and undergraduate astrophysics programs at the University of Pittsburgh will be carried out. The principle goals of these programs are:o To quantify how the properties of galaxies (their spectral types, star formation and luminosities) evolve from a redshift of z = 0 to z = I and to determine what physical processes drive these changes.o To trace the clustering of galaxies at low and intermediate redshifts (z 1) as a function of lookback time, galaxy type and environment and to relate these observations to current cosmological theories of galaxy formation and evolution.o To develop the new virtual observatories into an undergraduate and graduate research and teaching environment (a "virtual telescope"). One that enables students to undertake exploration of online astrophysical databases at their own pace.o To integrate computational sciences into astrophysics to enable a cross-fertilization of ideas and tech-niques at the graduate and undergraduate level.This project is funded by the Division of Astronomical Sciences.***