United States-sized telescope views structure of Milky Way’s black hole

by William Atkins

Friday, 05 September 2008

Page 2 of 3 The work by these scientists lends important evidence that a black hole does exist at the center of our Milky Way Galaxy, and that its origin is located at or about Sagittarius A*. In the past, astronomers have assumed that a black hole exists at the center of our galaxy, but no direct evidence has been presented to verify the claim. Astronomers have had problems piercing the dense cloud of gases and dust in between the Earth and the center of the Milky Way--making it difficult to make any concrete measurements of its structure. In fact, Dr. Doeleman states, "This is the best black hole candidate that we have anywhere in the universe, the best chance we have to observe the kind of signatures we would expect around the immediate vicinity of a black hole. One of the problems with looking at this particular source is that we have to look through our galaxy. It's a blessing that it's this close, but it's a curse because it's obscured by gas and dust." [MSNBC: “Scientists size up Milky Way’s black hole”] Researchers imaged the black hole using an array of radio telescopes a far distance apart. They connected them together so they worked as one telescope. Thus, the astronomers created a “virtual” telescope that is as wide as the continental United States, whose horizontal width is about 2,800 miles (4,500 kilometers). The three telescopes used for the project are: the Combined Array for Research in Millimeter wave Astronomy (CARMA) (California), the Arizona Radio Observatory (ARO), and the Submillimeter Array and James Clerk Maxwell Telescope (JCMT) (Hawaii). See how the three telescopes were brought together at Space.com's "Black Hole Telescope." Their results produced the most detail of the supermassive black hole at the Milky Way’s center ever produced. They were able to distinguish features in and around the black hole down to a length of about 30 million miles (or about one-third the distance between the Earth and the Sun). To bring it into better perspective, our solar system is about 26,000 light-years (52,800,000,000,000,000 miles) from the center of the galaxy. Such a resolution (ability to see details) by this array of telescopes would be similar to being able to see a U.S. flag left on the Moon from a location on Earth (a distance of about 240,000 miles [386,000 kilometers]). Doeleman stated, “The new observations we made confirm, for the first time, that there is structure on these scales in Sagittarius A*.” [Science News (subscription required): “Milky Way's black hole seen in new detail”] The findings also help to gather more evidence that the center of the Milky Way galaxy does indeed contain a supermassive black hole. Astronomers call the work a very important advance in black hole physics. Page three contains information about the black hole's event horizon, the structure that sucks light and everything else into the black hole. << First page <   1 2 3 Next page > Last page - Post your comment >>

 

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