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Studies of galaxies giving rise to QSO absorption systems and observations of the high-redshift universe.

机译：对引起QSO吸收系统的星系的研究以及对高红移宇宙的观测。

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摘要

I present a study of the galaxies that give rise to Lyman-alpha (Lyalpha) and triply ionized carbon (CIV) absorption lines observed in the spectra of background quasi-stellar objects (QSOs), as well as on studies of the high-redshift universe. By comparing the redshifts of galaxies and Lyalpha absorption systems along common lines of sight, I confirmed the existence of an anti-correlation between Lyalpha absorption equivalent width and galaxy impact parameter. Further analysis showed that tenuous gas is likely to be distributed around galaxies in spherical halos rather than in flattened disks with the gaseous extent scaling with galaxy B-band and K-band luminosities. I found that extended gaseous halos are a common and generic feature of galaxies over a wide range of luminosity and morphological type and Lyalpha absorption systems traced a significant and representative portion of the galaxy population. Applying the scaling relation between galaxy gaseous radius and galaxy B-band luminosity to predict the incidence of Lyalpha absorption systems originating in extended gaseous envelopes of galaxies, I found that luminous galaxies can explain about 50% of Lyalpha absorption systems with absorption equivalent width W > 0.3 A.; By comparing the redshifts of galaxies and CIV absorption systems along common lines of sight, I found that extended gaseous halos of galaxies have been metal contaminated out to large galactocentric radii, ≈100 h-1 kpc. The covering factor of ionized gas in galactic halos was estimated to be 0.93 with a 1 sigma lower bound of 0.83, which may strongly constrain the possibilities that CIV absorption systems arised in accreting satellite galaxies or in filaments of gravitationally collapsed structures.; To study the high-redshift universe, I analyzed very deep slitless spectroscopy observations acquired by the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. These observations are especially suited for identifying very distant galaxies due to high sensitivity and less contaminating background light. A galaxy at z = 6.68 and five emission-line objects at ⟨z⟩ = 4.69 were identified in this field, providing constraints on star formation in the early universe.
机译：我提出了对在背景准星体（QSO）光谱中观察到的产生Lyman-α（Lyalpha）和三重离子化碳（CIV）吸收线的星系的研究，以及对高红移的研究宇宙。通过比较沿共同视线的星系和Lyalpha吸收系统的红移，我证实了Lyalpha吸收当量宽度与星系撞击参数之间存在反相关。进一步的分析表明，随着气态程度随银河系B波段和K波段的光度变化，微弱的气体很可能会分布在球形光晕中的星系周围，而不是分布在平坦的圆盘中。我发现，扩展的气态光晕是银河系在广泛的光度和形态类型上的普遍特征，Lyalpha吸收系统追踪了银河系人口的重要部分。利用星系气体半径和星系B波段光度之间的比例关系来预测起源于星系扩展气体包膜的Lyalpha吸收系统的发生率，我发现发光星系可以解释吸收等效宽度为W>的Lyalpha吸收系统的约50％。 0.3安通过比较星系和CIV吸收系统沿共同视线的红移，我发现星系的扩展气态光晕已被金属污染，形成大的以银河为中心的半径，aph为100 h-1 kpc。估计银河晕中离子化气体的覆盖因子为0.93，1σ下界为0.83，这可能强烈限制了CIV吸收系统在吸积卫星星系或重力坍塌结构的细丝中出现的可能性。为了研究高红移宇宙，我分析了哈勃太空望远镜上由太空望远镜成像光谱仪获得的非常深的无狭缝光谱观测。由于高灵敏度和较少污染的背景光，这些观测值特别适合于识别非常遥远的星系。在该场中确定了一个z = 6.68的星系和〈z = 4.69的五个发射线天体，这限制了早期宇宙恒星的形成。

著录项

  • 作者

    Chen, Hsiao-Wen.;

  • 作者单位

    State University of New York at Stony Brook.;

  • 授予单位 State University of New York at Stony Brook.;
  • 学科 Physics Astronomy and Astrophysics.
  • 学位 Ph.D.
  • 年度 1999
  • 页码 182 p.
  • 总页数 182
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 天文学;
  • 关键词

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