Quasars and the Early Evolution of Massive Galaxies

AST-0305833 BaldwinQuasar发射线提供了一种追踪年轻大质量星系中心区域强烈演化的物理条件的方法。宽发射线区域（BELR）中的气体应该揭示了它所来自的宿主星系的化学演化，并且观测到的发射线对该区域的未知结构不敏感。 BELR谱线强度也直接反映了宿主星系中心的动力学演化速率。 这些谱线的亮度意味着即使在相当大的红移下也可以精确测量，但它们很难解释。 PI将进一步检查他多年来一直在开发的解释方法，并将进行数值实验，以确定使用的最佳线，并校准铁丰度作为计时器的使用，以及了解BELR衍生特性的真正不确定性。 有了这些结果，优化的观测将获得精心挑选的样本的高质量光谱，并获得可以直接揭示大质量星系中心早期演化的参数。PI将通过密歇根州立大学的艾布拉姆斯天文馆建立一个强大的公共宣传计划，使用一个华丽的，连续运行的演示文稿，以这项研究为背景，向每年成千上万的游客介绍宇宙学，星系的诞生和化学元素的起源 以此为基础，应该可以制作一个更广泛分布的天文馆节目，将达到更广泛的观众。

AST-0305833BaldwinQuasar emission lines offer a way to trace the strongly evolving physical conditions in the central regions of young massive galaxies. The gas in the Broad Emission Line Region (BELR) should reveal the chemical evolution in the host galaxy from which it has fallen, and the observed emission lines are not sensitive to the unknown structure of this region. The BELR line strengths also reflect directly the rate of dynamical evolution in the center of the host galaxy. The brightness of these lines means they can be measured precisely even out to quite large redshifts, but they have been hard to interpret. The PI will further check the interpretation methods he has been developing for some years, and will run numerical experiments to determine the best lines to use and to calibrate the use of iron abundances as a chronometer, as well as to understand the true uncertainties in the derived properties of BELRs. Armed with those results, optimized observations will obtain high quality spectra of a carefully selected sample, and derive parameters that can directly reveal early evolution at the centers of massive galaxies.The PI will set up a strong public outreach program through the Abrams Planetarium at Michigan State, using a flashy, continuously running presentation with this research as a background, to inform the thousands of annual visitors about cosmology, the birth of galaxies, and the origin of the chemical elements. With this as a basis it should be possible to produce a more widely distributed planetarium show that will reach an even broader audience.