Densely Sampling the High Redshift Universe

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。Steidel博士将对我们观测到的100亿年前明亮类星体附近几百万光年内的星系和气体进行详细的研究。利用凯克望远镜，他将采用高分辨率光学光谱和近红外光谱来测量我们和类星体之间气体的吸收线。这些光谱将以高电离氧谱线为目标来追踪温暖和热气体，莱曼- β谱线用来测量中性氢，还有额外的谱线用来探测气体中的化学丰度和物理条件。这些观测结果将与理论模型进行比较，以确定类星体等活动星系核对周围环境的影响。将拍摄深光学和近红外图像，以挑选可能靠近类星体的星系。这些天体的光学和红外光谱应该可以精确地得到每个类星体周围大约150个星系的红移（以及距离）、动态质量和化学丰度。当星系部分被尘埃遮挡时，红外光谱应该特别有效。两到三名研究生将在参与研究时接受培训。发表的结果和原始数据将尽快提供给天文学界。Steidel博士是MOSFIRE成像光谱仪（多目标红外探测光谱仪）的项目科学家；这台新仪器将服务于凯克天文台的广大用户群体。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Dr Steidel will make a detailed study of the galaxies and gas within a few million light years of bright quasars that we observe as they were 10 billion years ago. Using the Keck telescopes, he will take high-resolution optical and near-infrared spectra to measure the absorption lines of gas lying between us and the quasar. These spectra will target lines of highly ionized oxygen to trace warm and hot gas, Lyman-beta to measure neutral hydrogen, and additional lines that probe the chemical abundance and physical conditions in the gas. These observations will be compared with theoretical models for the effect that active galactic nuclei such as quasars should have on their surroundings. Deep optical and near-infrared images will be taken to pick out galaxies likely to lie close to the quasar. Optical and infrared spectra of these objects should yield accurate redshifts (and hence distances), dynamical masses and chemical abundances for about 150 galaxies around each quasar. The infrared spectroscopy should be particularly effective when the galaxies are partially obscured by dust. Two or three graduate students will be trained as they participate in the research. Both the published results and primary data will be made available as soon as possible to the astronomical community. Dr Steidel is Project Scientist for the MOSFIRE imaging spectrograph (Multi-Object Spectrometer for InfraRed Exploration); this new instrument will serve the Keck Observatory's large user community.