Detection of Middleweight Black Hole Forms Missing Link Evolution
With long time debates by scientists regarding the existence of middleweight black holes, the latest data that was gathered by the Hubble Space Telescope instruments and the Gemini South Chili telescope have shown us that the Omega Centauri, the largest star cluster in the sky, is observed to possibly contain an intermediate-mass black hole in its center. It is considered a prospective missing link in the evolution of our universe’s first stellar black holes, ending with the supermassive black holes where most major galaxies exist. In between are the possible middleweight black holes–never before detected.
The interesting thing about black holes is that they are observed only by their effects on surrounding stars or gas. Extremely dense, absolutely nothing can escape them—which includes light. Of the two classes of black holes that are known to exist. The stellar black holes weigh slightly more than the mass of the sun, while the supermassive ones are filled with millions/billions of solar masses.
Omega Centauri is not a new find by the Hubble telescope, it was listed as a single star about 2,000 years ago by the scientists of the time. In the year 1677, Edmond Halley changed the single star theory to one of a “nebula”. John Herschel, an English astronomer of the 1830s, changed this label of the Omega Centauri to a globular cluster, which contains about 10 million stars held together by gravity. The Omega Centauri is considered to be the largest and most massive of the 200 plus globular clusters which orbit the Milky Way, with the most ancient stars inhabiting it—the remnants of the early Universe.
The calculation of the Omega Centauri’s total mass was higher than expected, based on its number and type of stars observed. This was detected when Noyola and her colleagues measured the velocities of stars within the cluster’s center. A suspicion of the missing mass’s origin was from a black hole, weighing 40,000 solar masses at the center, was developed by the research crew. In regard to the missing mass, other explanations were considered—such as a collection of unseen burnt out stars [white dwarfs or neutron stars] or even a group of stars with elongated orbits. The latter would involve the stars closest to the center, forming an appearance of speeding up and an overestimation of the mass. But these last two explanations were not ones that met with Noyola’s favor, feeling they were unlikely.
This entry was posted on Friday, April 11th, 2008 at 1:16 am and is filed under Space Agency News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
