Tracing Evolution of Metals and Stars in Galaxies with Quasar Absorption Lines

星系的演化和宇宙中化学元素的产生是天体物理学和宇宙学的基本问题。一个追踪星系中恒星、气体和金属演化的强大工具是由位于类星体视线上的阻尼莱曼α (DLA)和次DLA吸收器的光谱线提供的。星系演化模型的基本测试来自于限制星系中金属和恒星的宇宙密度。目前，DLA的观测结果与大多数宇宙化学演化模型的预测相矛盾。然而，现有的低红移样品仍然相对较小，并且包括太少的亚dla或尘埃dla，并且对吸收剂的高分辨率成像研究很少。该项目将通过获得具有已知中性氢柱密度的低红移dla和亚dla大样本的高分辨率光谱和成像观测来研究这些问题。这将通过限制星系中金属和恒星的宇宙密度，为星系演化模型提供基础测试。这项研究将使用可公开获得的档案数据以及将从最先进的设施获得的新数据。南卡罗来纳大学的研究生和本科生的研究培训带来了教育效益，因为该地区的天文学家很少，尤其是少数族裔或女性天文学家。因此，该项目为弱势群体提供了独特的职业发展、招聘和指导机会。首席研究员还将继续积极开发新的研究生和高级本科课程，并通过南加州大学梅尔顿天文台和南卡罗来纳州立博物馆开展广泛的外展活动。

AST-0607739KulkarniThe evolution of galaxies and the production of chemical elements in the Universe are fundamental issues in astrophysics and cosmology. A powerful tool for tracing the evolution of stars, gas, and metals in galaxies is provided by the spectral lines of damped Lyman-alpha (DLA) and sub-DLA absorbers that lie along the sightlines to quasars. Fundamental tests of galaxy evolution models come from constraining the cosmic density of metals and stars in galaxies. At present, DLA observations contradict the predictions of most cosmic chemical evolution models. However, the existing low-redshift samples are still relatively small, and include far too few sub-DLAs or dusty DLAs, and there have been very few high-resolution imaging studies of the absorbers. This project will investigate these issues by obtaining high-resolution spectroscopic and imaging observations for a large sample of low-redshift DLAs and sub-DLAs with known neutral hydrogen column densities. This will provide fundamental tests of galaxy evolution models by constraining the cosmic density of metals and stars in galaxies. This research will use publicly available archival data as well as new data to be obtained at state-of-the-art facilities.Educational benefits accrue from the research training of graduate and undergraduate students at the University of South Carolina, in a region with very few astronomers, and especially very few minority or women astronomers. Thus, the program provides unique career advancement, recruiting, and mentoring opportunities for under-represented groups. The Principal Investigator will also continue active development of new graduate and upper level undergraduate courses, and her extensive outreach activities through the USC Melton Observatory and the South Carolina State Museum.