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

• 批准号: 9970873
• 负责人: David Turnshek
• 金额: $ 28.74万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-15 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9970873&HistoricalAwards=false
• 关键词: Ground; Based; Observations; Low; Redshift

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.

低红移阻尼莱曼α系统的地面观测准恒星物体（QSO）的观测显示吸收线的图案。 这些线起源于分布在整个宇宙中的居间气体区域。 由于氢的莱曼α系列，它们呈现为谱线。 这些谱线中的绝大多数是窄的莱曼α谱线。 有时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，界限并不那么狭窄。 Turnshek博士建议用地面设施跟踪已知的低红移阻尼莱曼α系统，以便阐明这些星系的各种性质：光度和从类星体视线的分离，HI横截面，和每共动体积的星系数;星系形态，表面亮度，颜色，恒星种群和星星形成率;元素丰度和尘埃;和21厘米自旋温度和21厘米金属线运动学。 各种各样的接受和计划的地面计划计划使用几个地面望远镜。