How does a gamma ray get converted to visible light

[Clara Chung]

In the process of heat transfer from core to photosphere, each gamma ray in the Sun's core is converted during scattering into several million visible light photons before escaping into space.----from Wikipedia

How does heat transfer related to scattering? Is it related to Raman scattering as the energy of gamma ray decreases?

 

[phyzguy]

It is primarily Compton scattering of the photons off the free electrons which are present. The electrons also scatter off the heavier ions and produce lower energy photons through bremsstrahlung. These processes happen a huge number of times until the electron gas and the photon gas are in thermal equilibrium. At each radius, the photons and the electrons are in thermal equilibrium, but as you progress out from the core of the sun to the photosphere, the temperature of the photon gas (and the electrons and ions) gets steadily lower until it is approximately 5000 K near the surface, where the photon energy peak is in the visible region.