Blowtorch of the Gods Captured by Black Hole Image Makers

Dr. Kim’s group has now reprocessed the observations from those four nights. In addition the group used two other sets of radio telescopes at different frequencies and different resolutions on other days. They did this to study the structure of the quasar’s jet and zoom in on its source, like opening a set of Matryoshka dolls, in Dr. Kim’s words.

The results can be seen in the movie above. As viewed from afar at the lowest magnification, the jet bends down from a bright spot at the top of the frame, which corresponds to the center of the quasar, where the black hole is presumably working its grinding magic. Seen closer up, the jet decomposes into a series of blobs or hot spots shooting out. They form a line that bends slightly.

Under the highest magnification, the viewer is left with two blobs — one at the top of the image, which is source of the jet, and the lower feature, which is one of the jet’s outbursts of energy. The source of the jet looks like a bar turned sideways, nearly perpendicular to the direction of the blowtorch.

That, Dr. Kim said in a statement, was a surprise, because they found this unexpected, perpendicular form where they expected to find only the source of the jet.

“This is like finding a very different shape by opening the smallest Matryoshka doll,” he said.

The perpendicular structure, the astronomers said in their paper, could be the accretion disk itself, the doughnut of fiery doomed material that circles the black hole. Enormous pressures and magnetic fields in that realm squeeze energy out the top and bottom of the doughnut at nearly the speed of light.

Dr. Doleman ventured, however, that it could just be the beam twisting again to make life difficult for the observers.

In the second half of the movie, the astronomers compared images from the Event Horizon Telescope at a single wavelength over the course of a week to see how the knots in the jet were moving.

source: nytimes.com