When forces battle on a galactic scale, the combatants must be titans.

And so they are in a galaxy known as Cygnus A, where a massive black hole dukes it out with a gigantic bubble of gas. Gravity and pressure are the weapons.

The result, captured in a newly released image from the Chandra X-ray Observatory, is a galaxy-enveloping cocoon of hot gas, pushed outward by two jets of energy and punctuated by a pair of bright "hot spots."

"This is a spectacular cavity, which is inflated by jets and completely surrounds the Cygnus A galaxy," said Andrew Wilson, an astronomy professor at the University of Maryland. "We are witnessing a battle between the gravity of the Cygnus A galaxy, which is trying to pull the hot gas inwards, and the pressure of material created by the jets, which is trying to push the hot gas outwards."

Cygnus A is about 700 million light-years away and has long been known as the brightest source in the sky for radio emissions. It is part of a cluster of galaxies separated by hot gas -- tens of millions of degrees Celsius.

Researchers suspect that a black hole at the center of the galaxy is the root of all the activity. Black holes are incredibly massive objects that suck nearly all nearby matter inward. As gas swirls toward the center in what's called an accretion disk, it becomes magnetized. Some of this material is thought to be spit out in opposite directions, in two powerful jets of energy.

These jets slam into more gas that's being sucked inward, carving the cavernous bubble around Cygnus A. And, for now at least, pressure is the victor over gravity.

The two jets crash into the bubble of gas about 300,000 light-years from the galaxy's center, creating a pair of hot spots and forcing the bubble to expand continuously, even as the black hole tries to suck it inward. Researchers had seen these hot spots previously in radio wavelengths, but could not explain them.