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

低红移阻尼莱曼α系统的地面观测对类星体（QSO）的观测显示了吸收线的模式。这些线起源于分布在整个宇宙的中间气体区域。由于莱曼α系列的氢，它们以光谱线的形式出现。这些谱线绝大多数是狭窄的莱曼α谱线。偶尔，人们会看到一条线从一个非常密集的区域出现。在这些情况下，界限并没有那么窄。这些是阻尼莱曼α系统。Turnshek建议用地面设施跟踪已知的低红移阻尼Lyman α系统，以阐明这些星系的各种特性：光度和与QSO视线的距离、HI横截面和每移动体积的星系数量；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；21厘米的旋转温度和21厘米的金属线运动学。各种各样已被接受和计划的地面项目都计划使用几个地面望远镜。

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.