Absorption-line Gas: Combining Models and Observations

该项目的PI和co-PI将结合观测和理论努力，以了解普通（重子）物质如何在不同环境下流入和流出星系。该项目的观测部分将集中在斯隆数字巡天（SDSS）中发现的星系上，这些星系具有已知的恒星形成特性，背后有类星体。通过获得类星体的光谱，分析星系中曾经电离的镁（Mg II）和中性钠（Na I）的吸收谱线，他们将确定流入或流出特征的空间范围，以及它们是否与恒星形成速率或环境相关。他们还将利用SDSS和DEEP2巡天的光谱，分析低光度星系的Na I D线。该项目的理论方面将使用宇宙流体动力学模拟来计算Mg和Na线的模型轮廓，以解释观测结果并识别“冷流”吸积的特征。这项研究的结果将为下一代地面望远镜的设计提供科学依据。此外，作为加州州立数学与科学暑期学校的讲师，PI和co-PI将利用他们的研究内容为高中生开发一个实验室项目。

The PI and co-PI of this project will combine observational and theoretical efforts to understand how ordinary (baryonic) matter flows into and out of galaxies in different environments. The observational side of the project will focus on galaxies identified in the Sloan Digital Sky Survey (SDSS) with known star-forming properties that have quasars behind them. By obtaining spectra of the quasars and analyzing absorption lines due to once-ionized magnesium (Mg II) and neutral sodium (Na I) in the galaxies, they will determine the spatial extent of inflow or outflow signatures and whether they are correlated with star formation rate or environment. They will also analyze the Na I D line in lower luminosity galaxies, using spectra from the SDSS and DEEP2 surveys. The theoretical side of the project will use cosmological hydrodynamic simulations to calculate model profiles of the Mg and Na lines, in order to interpret the observations and identify signatures of "cold flow" accretion. The results from this study will inform the science justifications for, and implicitly the design of, next-generation ground-based telescopes. Also, the PI and co-PI, as instructors in the California State Summer School for Mathematics and Science, will develop a laboratory project using elements of their research for high-school students.