PHOTOS: The Most Mind-Blowing Space Spirals
They're thought to be the result of jets firing from the poles of an ultramassive black hole at the center of the elliptical galaxy, a staggeringly large (that is, massive) object containing the equivalent mass of over 10 billion suns.
Put another way, that one black hole could itself contain nearly one-tenth of all the stellar masses in our entire galaxy, if all stars were like our sun (even though they aren't). Still, that's an incredible cosmic beast.
A black hole of that magnitude and mass would, especially if it is spinning rapidly, fire powerful, twisting jets of energy and matter from its poles far, far out into space. These jets - which have been observed in radio frequencies with the NSF's Very Large Array (VLA) - travel at supersonic speeds through the surrounding gas, blowing it aside and leaving the large cavities seen by Chandra.
NEWS: Massive Black Holes are Everywhere!
In addition to making galaxy-sized holes, the jets and the shockwaves they create keep the hot gas in the cloud from cooling and condensing to form trillions of new stars.