For "cooling by radiation" there's, counterintuitively, laser cooling: https://en.wikipedia.org/wiki/Laser_cooling https://en.wikipedia.org/wiki/Laser_cooling

For "cooling by radiation" there's, counterintuitively, laser cooling: https://en.wikipedia.org/wiki/Laser_cooling https://en.wikipedia.org/wiki/Laser_cooling "Laser cooling relies on the change in momentum when an object, such as an atom, absorbs and re-emits a photon (a particle of light). For an ensemble of particles, their thermodynamic temperature is proportional to the variance in their velocity. That is, more homogeneous velocities among particles corresponds to a lower temperature. Laser cooling techniques combine atomic spectroscopy with the aforementioned mechanical effect of light to compress the velocity distribution of an ensemble of particles, thereby cooling the particles."