New Windows on Damped Lyman Alpha Protogalaxies

这项研究的主要结果将是确定正常星系从现在到红移5左右的恒星形成历史。这之前是用最明亮的星系来做的，但是一项新的技术通过观察阻尼莱曼α系统（DLAs）来获得更能代表原星系质量分布的物体的恒星形成率（SFRs），这是一群在吸收背景类星体时检测到的气体中性氢层。该方法将用于考虑大量问题，包括SFR如何随红移而变化，如何与来自发光星系的结果进行比较，SFR如何依赖于质量，中性氢柱密度，速度宽度和金属丰度，如何与理论预测进行比较，恒星形成是否局限于中央凸起或发生在整个吸收气体中，以及dla是否在空间上与发光星系相关。所有的研究结果最终将进入一个普遍可访问的数据库，该数据库已被其他研究人员使用。这些项目涉及不同层次的学生，以及初级研究人员，包括一些来自代表性不足的群体的研究人员

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.***