Final answer:
Radio emissions at the center of the Galaxy primarily come from Sagittarius A* and the high-speed electrons traveling through strong magnetic fields.
Step-by-step explanation:
Most of the radio emissions from the center of the Galaxy come from the sources: Sagittarius A* and regions with high-speed electrons in strong magnetic fields. Sagittarius A*, or Sgr A*, is the very bright radio source in the nucleus of the Galaxy, surrounded by hot gas heated by clusters of hot stars or by supernova blast waves. The other main source is high-speed electrons in strong magnetic fields producing bright thin arcs and threads, which can often be seen on radio images of the galactic center.