In the Sunyaev–Zeldovich effect, photons from the cosmic microwave background ra
ID: 3161184 • Letter: I
Question
In the Sunyaev–Zeldovich effect, photons from the cosmic microwave background radiation are Compton upscattered in energy by hot electrons in a cluster along the line of sight. Assume 0.001 of the photons are scattered, and the mass of the cluster is 2 × 1014M, of which 15% is in the hot gas (fully ionized hydrogen).
a. Use the Thomson cross section to represent the cross section for Compton scattering, and assume the cluster is spherical and of constant density, to find the diameter of the cluster (assume the photons pass through one diameter).
3. In the Sunyaev-Zeldovich effect, photons from the cosmic microwave background radi- ation are Compton upscattered in energy by hot electrons in a cluster along the line of sight. Assume 0.001 of the photons are scattered, and the mass of the cluster is 2 x 14 Mo, of which 15% is in the hot gas (fully ionized hydrogen). a. Use the Thomson cross section to represent the cross section for Compton scattering, and assume the cluster is spherical and of constant density, to find the diameter of the cluster (assume the photons pass through one diameter).Explanation / Answer
thompson cross section= 8 (pi) r2 /3 here r is electron radius.
when the photon energy is equal to or greater the rest mass energy of electronen, then the compton scattering occurs.
the differential cross section for compton was derived by klein-nishina formula.
thomson scattering is the elastic scattering of light by free charged particles