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courses:ast403:sunyaev-zeldovich-sz-effect [2026/03/10 07:23] – [Physical Mechanism] shuvocourses:ast403:sunyaev-zeldovich-sz-effect [2026/03/10 07:38] (current) – [Mathematical Formulation] shuvo
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 // The Dimensionless Frequency ($x$):// \\ // The Dimensionless Frequency ($x$):// \\
 +
 +$$x = \frac{h\nu}{k_B T_{cmb}} \approx \frac{\nu}{56.8 \text{ GHz}}$$
 +
 The function $f(x)$ determines the shape of the spectral distortion: The function $f(x)$ determines the shape of the spectral distortion:
  
  
-$$x = \frac{h\nu}{k_B T_{cmb}} \approx \frac{\nu}{56.8 \text{ GHz}}$$ 
  
 $$f(x) = \left( x \frac{e^x + 1}{e^x - 1} - 4 \right)$$ $$f(x) = \left( x \frac{e^x + 1}{e^x - 1} - 4 \right)$$
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-[{{ :courses:ast403:sze_total.png?600 | Fig 1: Plots showing individual and total SZ effects.}}]+[{{ :courses:ast403:sze_total.png?600 | Fig 2: Plots showing individual and total SZ effects.}}]
  
 ===== Observational Characteristics ===== ===== Observational Characteristics =====
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 2. Map Large Scale Structure: Detecting clusters that are too faint to see in visible light.\\ 2. Map Large Scale Structure: Detecting clusters that are too faint to see in visible light.\\
 3. Study Dark Energy: Tracking how the number of clusters has grown over cosmic time. 3. Study Dark Energy: Tracking how the number of clusters has grown over cosmic time.
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 +
 +
 +===== Composite Observational Analysis of Galaxy Cluster "COMA-B1" =====
 +
 +[{{ :courses:ast403:sze_cluster.png?600 | Fig 3: This infographic illustrates the multi-messenger approach used to study the Intra-Cluster Medium (ICM) and calculate cosmological distances.}}]
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 +**Primary Map (Center):** A simulated 30-arcminute field of view showing the tSZ Decrement (dark blue) at $z=0.45$. The background "noise" represents the primary fluctuations of the CMB, while the central void is the "shadow" cast by the cluster. Overlaid white contours show the X-ray Surface Brightness, highlighting the higher-density core where $n_e^2$ emission dominates.\\
 +**Cluster Profiles (Top-Left):** A comparison of the radial distribution of the three primary signals. The Thermal SZ profile shows a broad pressure distribution, while the X-ray profile is more peaked toward the center. The Kinematic SZ profile remains nearly flat, reflecting the uniform bulk velocity of the cluster's gas.\\
 +**SZ Spectrum (Bottom-Left):** The characteristic spectral "S-curve" of the Sunyaev-Zeldovich effect. It identifies the Null Point (~217 GHz), which serves as the transition between the low-frequency intensity decrement and the high-frequency intensity increment.\\
 +**Scale and Mass (Right):** The color bar indicates a peak temperature deviation of $-750 \mu\text{K}$, typical for a massive system of $10^{15} M_{\odot}$. This data, when combined with X-ray luminosity, allows for an absolute distance measurement independent of the cosmic distance ladder.
  
  
courses/ast403/sunyaev-zeldovich-sz-effect.1773148991.txt.gz · Last modified: by shuvo

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