Using a new and more powerful supercomputer, a Northwest University professor (among other researchers) have gained knowledge concerning the enigmas that are black holes. They specifically have gained insight into the jets that shoot from black holes which can extend for millions of light years.
Since the time humans first discovered black holes, they have always been mysterious and unknown. Even with our amazing progression in technology, we still do not fully understand them. For instance, it is known that there are jets that protrude from black holes that seem to extend very far into space. It was not known, however, if these jets follow an exact behavior or not.
"Understanding how rotating black holes drag the space-time around them and how this process affects what we see through the telescopes remains a crucial, difficult-to-crack puzzle," said Alexander Tchekhovskoy, assistant professor of physics and astronomy at Northwestern's Weinberg College of Arts and Sciences. "Fortunately, the breakthroughs in code development and leaps in supercomputer architecture are bringing us ever closer to finding the answers."
Recent research has shown that the jets gradually change direction in the sky, rather than remaining constant. Logically, scientists have always understood the fact that the jets could not remain in a straight line since the space around the black hole is being dragged into the black hole thus causing a sort of rotation around the hole. This rotation was known to the world ever since Einstein’s fairly accurate prediction about extreme gravity being located near black holes that are rotating, which was a part of his theory of general relativity.
In order to understand the behavior of the jets, one must understand exactly what the jets are. The jets are the black hole’s way of releasing the energy in stores after taking in matter. A popular analogy would be that it is like the whirlpool that is formed as water circles and eventually goes down the drain. The magnetic fields and gas that “feed” - for lack of a better term - the black hole swirl which then forms a rotating disc.
The black hole then engulfs the matter which is usually just a massive gas cloud or two from time to time. The matter could be thought to have calories which add energy to the black hole which have to exit the system one way or another such as with the human body. The only difference is that black holes emit energy in the form of jets that reach millions of light years across the universe but are not actually considered to be black holes themselves.
Why are the researchers focusing so much on the jets of the black hole rather than the actual black hole? The jets are actually a lot easier to study than black holes. Also, studying jets actually helps shed light on the nature of black holes. Essentially, researchers are taking black hole research a few steps at a time and the first of its kind supercomputer will allow them to progress a few steps farther. The computer simulation helped reveal how quickly the jets change direction which actually helped scientists understand the spin of the black hole itself.
Previous simulations have not been so successful in creating an accurate picture of black holes. This is due to the fact that other simulations went off the assumption that all black holes had aligned discs (or the rotation factors), but this most recent simulation considers the fact that most black holes have been found to have tilted discs instead.
This simulation was also groundbreaking due to the fast code it harbors. In other words, the simulation was made to be in the highest resolution possible with astounding GPU architecture to make the most accurate prediction possible as to the behavior of the jets.
"The high resolution allowed us, for the first time, to ensure that small-scale turbulent disk motions are accurately captured in our models," Tchekhovskoy said. "To our surprise, these motions turned out to be so strong that they caused the disk to fatten up and the disk precession to stop. This suggests that precession can come about in bursts."
The models and predictions produced by this one simulation are currently helping scientists studying black holes right now all over the world. This simulation could be further progressed to allow for accurate studies of black holes themselves.