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courses:ast403:absorption-systems [2026/03/23 22:19] – [The Gunn-Peterson Trough] shuvocourses:ast403:absorption-systems [2026/03/26 07:03] (current) – [Infographics on Absorption Systems] shuvo
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 **Cosmological Significance:** These clouds are the most common type of absorption system and represent a significant reservoir of the Universe's baryons. They also show traces of "missing metals"—pollutants from early star formation found even far from galaxies. **Cosmological Significance:** These clouds are the most common type of absorption system and represent a significant reservoir of the Universe's baryons. They also show traces of "missing metals"—pollutants from early star formation found even far from galaxies.
  
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 +[{{ :courses:ast403:lymanforest.png?600 | Fig 2: Lyman-alpha forest.}}]
  
 Here is a video of how this is generated: [[https://youtu.be/6Bn7Ka0Tjjw?si=6O0a9UhoEDe6JY4x]] Here is a video of how this is generated: [[https://youtu.be/6Bn7Ka0Tjjw?si=6O0a9UhoEDe6JY4x]]
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-[{{ :courses:ast403:lymanasb.jpeg?600 | Fig 2: Spectrum foa quasar at z=1.34 showing various Lyman absorptions.}}]+[{{ :courses:ast403:lymanasb.jpeg?600 | Fig 3: Spectrum foa quasar at z=1.34 showing various Lyman absorptions.}}]
 ===== Lyman-Limit Systems ===== ===== Lyman-Limit Systems =====
 These systems have column densities of $N(HI) \gtrsim 2 \times 10^{17} \text{ cm}^{-2}$. \\ These systems have column densities of $N(HI) \gtrsim 2 \times 10^{17} \text{ cm}^{-2}$. \\
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-[{{ :courses:ast403:lymanasb.png?600 | Fig 3: Various absorption systems. See [[https://arxiv.org/abs/1510.03368]] for details.}}]+[{{ :courses:ast403:lymanasb.png?600 | Fig 4: Various absorption systems. See [[https://arxiv.org/abs/1510.03368]] for details.}}]
  
 ===== The Gunn-Peterson Trough ===== ===== The Gunn-Peterson Trough =====
 In the spectra of the most distant quasars ($z \gtrsim 5.8$), the $Ly\alpha$ forest becomes so dense that the individual lines blend into a continuous region of zero flux. This Gunn-Peterson trough indicates that the light is passing through diffuse neutral hydrogen that has not yet been fully ionized, marking the final stages of the epoch of reionization. In the spectra of the most distant quasars ($z \gtrsim 5.8$), the $Ly\alpha$ forest becomes so dense that the individual lines blend into a continuous region of zero flux. This Gunn-Peterson trough indicates that the light is passing through diffuse neutral hydrogen that has not yet been fully ionized, marking the final stages of the epoch of reionization.
  
-[{{ :courses:ast403:gp_trough.jpg?600 | Fig 4: Gunn-Peterson trough.}}]+ 
 +[{{ :courses:ast403:gp_trough.jpg?600 | Fig 5: Gunn-Peterson trough.}}]
  
  
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 ===== Infographics on Absorption Systems ===== ===== Infographics on Absorption Systems =====
  
-[{{ :courses:ast403:absorption_systems.png?800 | Fig 4: IGM absorption systems explained.}}]+[{{ :courses:ast403:absorption_systems.png?800 | Fig 6: IGM absorption systems explained.}}]
courses/ast403/absorption-systems.1774325998.txt.gz · Last modified: by shuvo
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