A black hole pulls material off of the star it "eats", creating an accretion disk. Artist's conception: http://upload.wikimedia.org/wikipedia/commons/2/2a/Accr

A black hole pulls material off of the star it "eats", creating an accretion disk. Artist's conception: http://upload.wikimedia.org/wikipedia/commons/2/2a/Accretion_disk.jpg http://upload.wikimedia.org/wikipedia/commons/2/2a/Accretion... But you're right- the bubbles are not the jets themselves. The bubbles would be interstellar gas energized by the relativistic particles. As the gas diffuses, it spreads from the jet's cone into a large bubble.