In understanding the distant parts of the cosmos, astronomers have been doing a pretty good job. In 2017 they made history as a global collaboration of scientists produced what is considered the very first direct image of a distant black hole. It was a historical moment that showed not only some of the wonders of the universe but that humans were capable of doing things that only a few decades ago were thought impossible.
Now, the scientists have a follow-up: the closest-ever image of a violent structure—a jet—spewed out of a supermassive black hole.
There a supermassive black hole at the center of a distant quasar located around 5 billion light-years away from us, called 3C 279. The optically variable quasar is known in the scientific community for its many variations in the visible, radio, and x-ray bands. Observed to have undergone a period of extreme activity from 1987 to 1991, the quasar is now again the center of astronomical observations.
Quasars are, in fact, some of the brightest cosmic objects we’ve ever come across: galaxies with gigantic black holes that produce intense radiation as gas in the accretion disk of the black hole is sucked towards a region called the event horizon.
Now, the collaboration of scientists that published the first black hole image has published new data. It’s actually from the same observational run that produced the first black hole image. The observations were made by the Event Horizon Telescope in April 2017.
The EHT was tuned to observe 3C 279 for a period of four nights. During this period, astronomer gathered relevant data from eight stations located at six different sites across the world. This data was then transferred to a supercomputer at the Max Planck Institute for Radio Astronomy, and MIT, where experts analyzed the plethora of information.
Their observations have now been published. When mater is sucked towards a powerful supermassive black hole, a very small fraction of the material is accelerated at nearly the speed of light. This phenomenon causes black holes to create something called “relativistic jets,” which can be described as cosmic structures, which are basically fastest-traveling particles in the known universe.
And precisely one off these jets was captured by astronomers of the EHT. They have managed to trace the Jet to the accretion disk of a black hole located at 3C 279. Although the image may not look much to us and is pretty blurry, it carries a plethora of unprecedented data that scientists will use to better understand black holes and relativistic jets.
One of the things astronomers found is although the Jet was supposed to look straight, the new image has revealed it actually has a slight bend at its base, together with an elongated structure that appears to be perpendicular to the direction of the Jet.
“This morphology can be interpreted as either a broad resolved jet base or a spatially bent jet. We also find significant day-to-day variations in the closure phases, which appear most pronounced on the triangles with the longest baselines. Our analysis shows that this variation is related to a systematic change of the source structure,” the researchers wrote in their study.
The observations were made over several days, and this allowed experts to identify changes that could be something that had been predicted by computer simulation, but never before directly observed: the rotation of the accretion disk and how the material is cut up as it gets sucked in into the black hole.
The results of the observations have been published in Astronomy & Astrophysics.