WATERLOO —
Avery Broderick, associate faculty member at the Perimeter Institute and the University of Waterloo, was part of a scientific team that, for the first time, produced imaging of a distant black hole and the area surrounding it.
“These are some of the most energetic objects in the universe, some of the most powerful objects in the universe, you could even say black holes are the engines of the cosmos,” Broderick said.
Black holes are areas of space where dense matter crushes down into a compact size, resulting in a mass that can be thousands to billions of times greater than the sun. These massive, dense objects create a gravitational pull so strong it prevents even light from escaping — appearing as black holes.
Aside from the interest in black holes spurred on by science fiction novels, scientists like Broderick have many questions about the existence of these objects. Why they occur and how they affect the growth of the galaxies they exist in are among the questions scientists are trying to answer.
“We would like to know how the evolution of the black holes themselves affects the evolutions of galaxies,” Broderick said.
To better understand black holes, scientists need to determine how they interact with the matter around them, whether or not they spin, the result of spin and what causes jets of light to be seen around the hole.
At 50 million light years in distance, Broderick and the team of scientists co-ordinated by Shep Doeleman at the Massachusetts Institute of Technology Haystack Observatory aimed to make visible some detail of the activity around a black hole in the M87 galaxy.
Their project — called the Event Horizon Telescope — resulted in the first empirical evidence connecting the spin of black holes and the jets they produce.
Until now, the connection only existed in theory.
For Broderick, these revelations are important steps toward defining the physics of black holes to answer the questions he has about gravitational theory.
“My big goal is I would like to learn enough about accretion and jet formation to remove them and test general relativity,” Broderick said.
General relativity — Einstein’s theory on gravitation — has passed wherever it’s been tested. But black holes offer a completely different environment where the theory may need adjustments in order to work.
While the recent data of the black hole in the M87 galaxy brings Broderick a step closer to understanding its physics, the image is far from clear.
“You can imagine it’s sort of like taking a picture and then blacking out all but a handful of pixels. With a handful of pixels it’s possible to tell the difference between your friend and your dog, but it might not be good enough to tell whose dog it really was,” Broderick explained.
Using a technique called Very Long Baseline Interferometry, the image was developed through data collected from multiple telescopes located on different corners of the planet that together acted as an Earth-sized telescope.
This technology that produced the current imaging data wasn’t possible 30 years ago, Broderick said, and it continues to improve.
With the ongoing construction of a new observatory in northern Chile that will eventually house over 60 radio telescopes and highly sensitive interferometer, the ability to develop a more detailed image of the black hole is in the near future.
“With that on board, we’re going to uncover many more of those pixels in that picture to the point that we will be able to say, ‘aha it’s a golden retriever, his name is Sparky,’ ” Broderick said.
“The goal ultimately is to have something that does produce a picture, that does take a snapshot.”
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