Evolution of the density-temperature distribution from the V21 model:

Now I turn off the photoheating from the UVB for \(z<6.2\)

Now I turn off the photoheating and photoionization from the UVB for \(z<6.2\)

Now I shift the UVB rates \(\Delta z ~ 1.0\) (Reionization happens at \(z\sim 7\) ) and turn off the photoheating and photoionization from the UVB for \(z<7.2\)

Now I shift the UVB rates \(\Delta z ~ 2.0\) (Reionization happens at \(z\sim 8\) ) and turn off the photoheating and photoionization from the UVB for \(z<8.2\)

Here is the evolution of \(T_0\) and \(\gamma\)