In a groundbreaking study released in Nature Astronomy, a team of researchers led by Eileen Meyer at the University of Maryland, Baltimore County, has challenged the prevailing theories about x-ray emissions from black hole jets. Artists principle illustration of a supermassive black hole emitting an x-ray jet. Credit: NASA/JPL-Caltech
Contradicting enduring theories, a current study has found that x-ray emissions from great void jets differ over brief periods, and take place throughout the jets rather than exclusively at their origin. The research study, based upon data from the Chandra X-ray Observatory, demands a reassessment of how particle acceleration operates in these jets and possibly the larger universe.
Researchers found just fairly recently that great void jets give off x-rays, and how the jets accelerate particles to this high-energy state is still a secret. Unexpected brand-new findings in Nature Astronomy appear to dismiss one leading theory, opening the door to reimagining how particle velocity operates in the jets– and potentially also elsewhere in deep space.
One leading design of how jets generate x-rays expects the jets x-ray emissions to remain stable over long time scales (countless years). However, the new paper found that the x-ray emissions of a statistically considerable variety of jets varied over simply a few years.
In a groundbreaking study released in Nature Astronomy, a team of scientists led by Eileen Meyer at the University of Maryland, Baltimore County, has challenged the prevailing theories about x-ray emissions from black hole jets. Artists idea illustration of a supermassive black hole giving off an x-ray jet. One model of how jets produce x-rays anticipates the jets x-ray emissions to remain stable over long time scales. In addition to presuming stability in x-ray emissions over time, the easiest theory for how jets create x-rays assumes particle acceleration happens at the center of the galaxy in the black hole “engine” that drives the jet. That recommends particle velocity is occurring all along the jet, at huge ranges from the jets origin at the black hole.
” One of the reasons were delighted about the irregularity is that there are 2 primary models for how x-rays are produced in these jets, and theyre entirely different,” discusses lead author Eileen Meyer, an astronomer at University of Maryland, Baltimore County. “One model invokes very low-energy electrons and one has really high-energy electrons. And one of those models is completely incompatible with any kind of variability.”
For the research study, the authors analyzed archival information from the Chandra X-ray Observatory, the highest-resolution x-ray observatory available. The research team took a look at nearly all of the great void jets for which Chandra had numerous observations, which amounted to 155 distinct areas within 53 jets.
Discovering relatively frequent variability on such short time scales “is revolutionary in the context of these jets, since that was not expected at all,” Meyer states.
The paper appears to rule out a leading theory for how black hole jets form x-rays. One design of how jets create x-rays expects the jets x-ray emissions to remain steady over long time scales. The brand-new paper discovered that the x-ray emissions of a statistically significant number of jets varied over simply a few years.
Reconsidering particle velocity
In addition to assuming stability in x-ray emissions in time, the easiest theory for how jets create x-rays assumes particle velocity takes place at the center of the galaxy in the black hole “engine” that drives the jet. The new research study discovered rapid modifications in x-ray emissions all along the length of the jets. That suggests particle velocity is taking place the whole time the jet, at large distances from the jets origin at the black hole.
” There are theories out there for how this might work, but a lot of what weve been dealing with is now clearly incompatible with our observations,” Meyer says.
Interestingly, the outcomes also hinted that jets closer to Earth had more variability than those much further away. It makes sense to Meyer that older jets would have less irregularity.
Critical collaboration
Chandra observed some of the pockets of variability with just a handful of x-ray photons. And the variability in x-ray production in a provided jet was usually 10s of percent or so.
” Pulling this outcome out of the information was practically like a miracle, due to the fact that the observations were not developed to find it,” Meyer says. The groups analysis recommends that in between 30 and 100 percent of the jets in the study showed variability over brief time scales. “While we would like better restraints,” she says, “the irregularity is especially not zero.”
The brand-new findings poke considerable holes in one of the major theories for x-ray production in great void jets, and Meyer hopes the paper spurs future work. “Hopefully this will be a genuine call to the theorists,” she says, “to generally have a look at this outcome and create jet designs that follow what were finding.”
Referral: “Variability of extragalactic X-ray jets on kiloparsec scales” 29 May 2023, Nature Astronomy.DOI: 10.1038/ s41550-023-01983-1.