Ground-Based Observations of Low-Redshift Damped Lyman-Alpha Systems

低红移阻尼莱曼阿尔法系统的地面观测类恒星天体(QSO)的观测显示了吸收谱线的模式。这些线起源于分布在整个宇宙的中间气态区域。由于氢的莱曼阿尔法系列，它们看起来像一条谱线。这些线中的绝大多数是狭窄的莱曼阿尔法线。偶尔，人们会看到一条从非常密集的区域出现的线条。在这些情况下，这条线并不是很窄。这些是受阻的莱曼阿尔法系统。特恩谢克建议利用地面设备对已知的低红移衰减莱曼阿尔法系统进行后续研究，以阐明这些星系的各种性质：光度和与类星体视线的分离、HI截面和每个自转体积的星系数量；星系形态、表面亮度、颜色、恒星数量和恒星形成率；元素丰度和尘埃；以及21厘米自转温度和21厘米金属线运动学。利用几个陆基望远镜计划了各种各样已被接受和计划的陆基项目。

Ground based observations of low redshift damped Lyman alpha systemsDavid TurnshekObservations of quasi stellar objects (QSO's) show patterns of absorption lines. These lines originate in the intervening gaseous regions distributed throughout the Universe. They appear as a spectral line due to the Lyman alpha series of hydrogen. The vast majority of these lines are narrow Lyman alpha lines. Occasionally one sees a line that arises from a very dense region. In these cases the line is not quite as narrow. These are the damped Lyman alpha systems.Dr. Turnshek proposes to follow up the known low redshift damped Lyman alpha systems with ground based facilities in order to elucidate various properties of these galaxies: luminosities and separations from the QSO lines of sight, HI cross sections, and number of galaxies per comoving volume; galaxy morphologies, surface brightnesses, colors, stellar populations, and star formation rates; element abundances and dust; and 21 cm spin temperatures and 21 cm metal line kinematics. A wide variety of accepted and planned ground based programs are planned using several ground based telescopes.