Electromagnetic radiation

Electromagnetic radiation (EM radiation for short) is a broad term for any type of radiation such as visible light, radio, microwave, gamma or X-rays. It is usually created by atomic nuclei when an electron orbiting them, excited by a quantum of energy, jumps to a higher energy level, becomes unstable, releases a photon of electromagnetic radiation, and returns to its original energy level. Pulsars emit various kinds of electromagnetic radiation. 

The warp field of a Federation starship like the USS Enterprise (NCC-1701-D) left behind an electromagnetic signature on Data's internal servo fluid system. 

In 2152, Doctor Phlox tried to free Jonathan Archer from a symbiotic lifeform using electromagnetic radiation, but to no avail. 

A time travel pod once visited the from the 31st century. Among other things, it was able to absorb electromagnetic radiation. 

Graviton ellipses are known to be attracted to electromagnetic radiation. The USS Voyager once reduced its power in order to lower the EM radiation levels and avoid one such ellipse.