courses:ast403:sunyaev-zeldovich-sz-effect
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| courses:ast403:sunyaev-zeldovich-sz-effect [2026/03/09 23:57] – shuvo | courses:ast403:sunyaev-zeldovich-sz-effect [2026/03/09 23:58] (current) – shuvo | ||
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| The SZ effect is typically divided into two components: the **Thermal (tSZ)** and the **Kinematic (kSZ)**. | The SZ effect is typically divided into two components: the **Thermal (tSZ)** and the **Kinematic (kSZ)**. | ||
| - | ** A. The Thermal SZ Effect (tSZ) | + | ** A. The Thermal SZ Effect (tSZ)**\\ |
| - | ** | + | |
| The tSZ effect is the primary distortion caused by the thermal motion of electrons. The change in the CMB brightness temperature ($\Delta T_{sz}$) at a frequency $\nu$ is given by: | The tSZ effect is the primary distortion caused by the thermal motion of electrons. The change in the CMB brightness temperature ($\Delta T_{sz}$) at a frequency $\nu$ is given by: | ||
| $$\frac{\Delta T_{sz}}{T_{cmb}} = f(x) \cdot y$$ | $$\frac{\Delta T_{sz}}{T_{cmb}} = f(x) \cdot y$$ | ||
| - | // The Dimensionless Frequency ($x$): | + | // The Dimensionless Frequency ($x$):// |
| - | + | ||
| - | // | + | |
| The function $f(x)$ determines the shape of the spectral distortion: | The function $f(x)$ determines the shape of the spectral distortion: | ||
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| * $m_e c^2$: Rest mass energy of an electron. | * $m_e c^2$: Rest mass energy of an electron. | ||
| - | **B. The Kinematic SZ Effect (kSZ) | + | **B. The Kinematic SZ Effect (kSZ)**\\ |
| - | ** | + | |
| If the entire galaxy cluster is moving with a bulk velocity ($v_z$) relative to the CMB rest frame, a second-order Doppler shift occurs: | If the entire galaxy cluster is moving with a bulk velocity ($v_z$) relative to the CMB rest frame, a second-order Doppler shift occurs: | ||
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| | Feature | Thermal SZ (tSZ) | Kinematic SZ (kSZ) | | | Feature | Thermal SZ (tSZ) | Kinematic SZ (kSZ) | | ||
| - | | --- | --- | --- | | ||
| | **Magnitude** | $\sim 1 \text{ mK}$ | $\sim 0.01 \text{ mK}$ | | | **Magnitude** | $\sim 1 \text{ mK}$ | $\sim 0.01 \text{ mK}$ | | ||
| | **Spectral Shape** | Frequency-dependent (unique " | | **Spectral Shape** | Frequency-dependent (unique " | ||
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| 1. Calculate the Hubble Constant ($H_0$): By combining SZ data with X-ray observations.\\ | 1. Calculate the Hubble Constant ($H_0$): By combining SZ data with X-ray observations.\\ | ||
| - | 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. | ||
courses/ast403/sunyaev-zeldovich-sz-effect.txt · Last modified: by shuvo