Researchers discovered only relatively recently that black hole jets emit X-rays, and how the jets accelerate particles to this high-energy state is still a mystery. Surprising new findings inappear to rule out one leading theory, opening the door to reimagining how particle acceleration works in the jets—and possibly also elsewhere in the universe.
For the study, the authors analyzed archival data from the Chandra X-ray Observatory, the highest-resolution X-ray observatory available. The research team looked at nearly all of the black hole jets for which Chandra had multiple observations, which amounted to 155 unique regions within 53 jets. Interestingly, the results also hinted that jets closer to Earth had more variability than those much farther away. The latter are so far away, that by the time the light coming from them reaches the telescope, it is like looking back in time. It makes sense to Meyer that older jets would have less variability. Earlier in the universe's history, the