Why must a charged particle be accelerated to produced photons?

[deadscientist]

Suppose you have an electron moving at constant velocity. This new area that it is moving into initially had 0 electric flux through it but now that the electron moves to that location the electric flux is changing which in turn cause a magnetic flux ad infinitum. So why must a charge be accelerated to produce photons if a constant velocity charge is constantly introducing a change in flux to an area? Thank you

 

[Khashishi]

If the electron is moving at constant velocity, you can Lorentz transform to a frame where the electron is not moving. Then there's only a static electric field. You can Lorentz transform back to the original frame and find a moving electric and magnetic field, but it isn't propagating as a wave.