New Windows on Damped Lyman Alpha Protogalaxies

这项研究的主要结果将是确定从现在到红移5左右的正常星系的星星形成历史。 这以前已经使用最明亮的星系完成，但一种新的技术推导出星星形成率（SFR）的对象更有代表性的原星系质量分布，通过观察阻尼莱曼α系统（DLAs），一个人口的气态中性氢层吸收到背景类星体。 这种方法将被用来考虑大量的问题，包括SFR如何随红移而变化，它如何与来自发光星系的SFR进行比较，SFR如何取决于质量，中性氢柱密度，速度宽度和金属丰度，它如何与理论预测进行比较，星星的形成是局限于中心凸起还是发生在整个吸收气体中，以及DLAs是否与发光星系在空间上相关。所有的结果最终都将被收录到一个普遍可访问的数据库中，其他研究人员已经在使用。 这些项目涉及各级学生以及初级研究人员，包括一些代表性不足的群体。

AST-0307824WolfeThe primary result from this research will be to determine the star formation history of normal galaxies from the present to redshifts around five. This has previously been done using the most luminous galaxies, but a new technique derives star formation rates (SFRs) for objects more representative of the protogalactic mass distribution, by observing damped Lyman alpha systems (DLAs), a population of gaseous neutral hydrogen layers detected in absorption toward background quasars. This method will be used to consider a large number of issues, including how the SFR varies with redshift, how it compares to that derived from luminous galaxies, how the SFR depends on mass, neutral hydrogen column density, velocity width and metallicity, how it compares to theoretical predictions, whether star formation is confined to the central bulge or occurs throughout the absorbing gas, and whether DLAs are spatially correlated with luminous galaxies.All results will end up in a generally accessible database, already in use by other researchers. The projects involve students at various levels, as well as junior researchers, including some from under-represented groups.***