Quasars

 Powerful radio emissions are usually associated with energetic processes, although not in a direct way. Observations at multiple wavelengths show that deep in certain galaxies there are extremely powerful sources of energetic particles. These particles interact with matter in the interstellar medium to produce copious amount of radiation, from radio waves, to visible light and energetic X-rays and gamma rays (recall that energy is inversely proportional to wavelength, thus short wavelength rays, such as X and gamma, have a lot of energy in them). One of the most mysterious of the objects emitting powerful beams of radiation is a quasar (quasi-stellar object). 
In the late '60s, powerful radio emitters were detected; they were named quasars; however, later work found that most quasars are not radio emitters. These objects have incredibly large red-shifts, indicating that they are moving at close the seed of light. 
By Hubble's law, it means they are very far away. Since they are so far away, they are also very far into the past, since light takes time to reach us, making these among the youngest objects seen. 
Quasars are still poorly understood objects. They reside in the center of faraway galaxies (1 and more million light-years away) and are believed to be caused by the presence of massive black holes. As matter rushes into black holes, it gets accelerated to very high speed and, in the 
interaction with the other material spiraling onto the black hole, emits enormous quantities of radiation, of which some is in the visible. Emissions in the X and gamma ray range are also observed.