Many galaxies (3C 75 among them) have strong radio emissions originating in their nuclei. Such “active galaxies” are thought to harbor black holes millions of times larger than the Sun. Astronomers theorize that material spirals into black holes and creates giant rotating accretion disks that heat to tremendous temperatures. By a process that is still not understood, highly energetic electrons stream out from near the disk and black hole and form radio jets, which are often much larger than the galaxies themselves. The electrons produce synchrotron emission detected by radio telescopes.
    3C 75’s sweeping radio emission pattern is entirely unlike its optical image. The first object of its kind