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Showing 1 to 3 of 3 for “"quasars: absorption lines"”.
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A synoptic survey of narrow quasar absorption lines from the Sloan Digital Sky Survey
… to study the properties of thousands of quasar absorption lines (QALs) in the time domain. Systems of QALs have proven to be one of the most sensitive and unbiased probes of baryonic matter in the high-redshift Universe. Short timescale absorption variability is one tool that has been used to …
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Properties of Galaxies Detected in Emission and Absorption with Background Quasars
… primordial gas. However, it is unclear how these absorption systems relate to present day galaxies. Observations of these systems detected through absorption in background quasar spectra indicate the DLAs are metal poor and slowly evolving while their counterparts, the sub-DLAs, are highly …
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The HI Lyman-alpha opacity at redshift 2.7 < z < 3.6
… that we can observe today, such as galaxies and quasars, are surrounded by the IGM in the most dense regions within the cosmic web. The radiation of these objects contributes to the so-called ultraviolet background (UVB) which keeps the IGM highly ionized ever since the epoch of reionization. …