For years, space has been a playground for astronomers and physicists to hypothesize about how known principles and theories of science act under a kaleidoscope of varying conditions. With the construction of the Event Horizon Telescope, scientists will be able to take a picture of the area known as Sagittarius A-star and determine whether or not a black hole, an area of space surrounded by a gravitational field from which nothing can escape, exists there.
Scientists from around the globe will assemble on Wednesday at the Westin La Paloma resort in Tucson for a conference organized by two UA professors: Dimitrios Psaltis, an associate professor of astrophysics, and Dan Marrone, an assistant professor of astronomy. The conference will address the Event Horizon Telescope, a worldwide network of telescopes built to take a picture of one of the Milky Way Galaxy’s black holes, the Sagittarius A-star.
The conference’s scientific organizing committee consists of 12 world-renowned researchers, including Marrone and Lucy Ziurys, a professor of astronomy and biochemistry whose research is at the forefront of the developing astrochemistry field.
Since a black hole is essentially a vacuum for all physical matter, including light particles, it is impossible to observe one with the naked eye. Up until now, a black hole has only been observed through gravitational lensing, a technique based upon Albert Einstein’s Theory of General Relativity, which looks for bent light as a result of the way a black hole’s mass bends the fabric of empty space.
Scientists, however, have designed the specific imaging equipment of the Event Horizon Telescope to detect and capture photos of emitted radiation from the matter passing through the black hole’s event horizon, or the point where its gravitational field is too strong to overcome. This outline of emitted radiation is known as a black hole’s “shadow.”
Seeing a picture of Sagittarius A-star’s shadow will define black holes as possessing either circular or oblate shapes. If the shape of the black hole is oblate, the relativity theory will need revising.
Scientists hope to understand the accretion process better with the concrete evidence produced by photos from the Event Horizon Telescope. These pictures should also help them to better understand the “jets” of light emitted by black holes.
Currently, the Event Horizon Telescope consists of linked radio telescopes positioned in Arizona, California and Hawaii as well as in Chile and Mexico, with more to be added. Radio telescopes are being used for this endeavor because radio waves pass through space objects to give researchers a clear view, something that is not possible with all forms of light. Also, constructing an optical telescope of this magnitude, while ideal, is not currently possible.
The actual date of the Event Horizon Telescope’s black hole photo shoot remains unsettled. After examining Sagittarius A-star, researchers will use the Event Horizon Telescope to penetrate a black hole in the Messier 87 galaxy.
