A team of European astrophysicists has been awarded nearly $20 million to construct the first accurate image of a black hole.
To create the image, the team will test the predictions on the dominant theories of gravity, including Einstein's theory of general relativity. By preforming these tests, the team will attempt to measure the shadow cast by the event horizon of the black hole at the center of the Milky Way galaxy, as well as find new radio pulsars near the black hole. The scientists will combine this data with simulated measurements of the behavior of light and matter around black holes as predicted by theories of gravity.
At the center of our galaxy, scientists know of a mysterious radio source called Sagittarius A*. It is believed that the source of the radio source is the center of the supermassive black hole at the center of the Milky Way. Although the black hole cannot be directly observed, the scientists can observe the area around the black hole, which will enable them to get an idea of what the black hole itself looks like. The team plans to image the event horizon, which is the border around a black hole where light can enter, but never leave. To gather the data, the astrophysicists will use a number of very powerful telescopes at various observatories around the world.
"While most astrophysicists believe black holes exist, nobody has actually ever seen one," said Heino Falcke, a professor in radio astronomy at Radboud University in Nijmegen and ASTRON, which is the Netherlands Institute for Radio Astronomy. "The technology is now advanced enough that we can actually image black holes and check if they truly exist as predicted: If there is no event horizon, there are no black holes."
Luciano Rezzolla, a professor of theoretical astrophysics at the Goethe University in Frankfurt, said the technological advances in the field of computational astrophysics has made this endeavor possible.
"We can now calculate very precisely how space and time are warped by the immense gravitational fields of a black hole, and determine how light and matter propagate around black holes," he said. "Einstein's theory of general relativity is the best theory of gravity we know, but it is not the only one. We will use these observations to find out if black holes, one of the most cherished astrophysical objects, exist or not. Finally, we have the opportunity to test gravity in a regime that until recently belonged to the realm of science fiction; it will be a turning point in modern science," Rezzolla said.
The grant awarded to finance the project, known as a Synergy Grant, is perhaps one of the most coveted awards offered by the European Research Council (ERC). The maxim value of a highly competitive Synergy Grant is 15 million euros; the black hole imaging project was awarded 14 million euros ($19.2 million). This is the first time an astrophysics proposal has been awarded a Synergy Grant.