Black hole bonanza: 10,000 objects near our galaxy's center.Thousands of superdense su·per·dense
Of or relating to an extreme condition in which matter is forced into nonclassical states, as when electrons are forced into protons, leaving only neutrons, or the matter is compressed beyond this point into a singularity. neutron stars and midget black holes lurk near the center of our galaxy, according to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. new X-ray studies of the sky. The stellar-mass black holes are each just 10 times the mass of the sun, much smaller than the supermassive black hole known to inhabit the Milky Way's center. That central black hole has an estimated mass of 3.7 million suns. Each neutron star is about the mass of the sun.
Using the orbiting Chandra X-ray Observatory Chandra X-ray Observatory
U.S. X-ray space telescope. It was named after astrophysicist Subrahmanyan Chandrasekhar and was launched into orbit in 1999. Its mirror, with an aperture of 1.2 m (4 ft) and a focal length of 10 m (33 ft), produces unprecedented resolution. , Michael P. Muno of the University of California, Los Angeles UCLA comprises the College of Letters and Science (the primary undergraduate college), seven professional schools, and five professional Health Science schools. Since 2001, UCLA has enrolled over 33,000 total students, and that number is steadily rising. (UCLA UCLA University of California at Los Angeles
UCLA University Center for Learning Assistance (Illinois State University)
UCLA University of Carrollton, TX and Lower Addison, TX ) and his colleagues found four dramatically flickering X-ray sources within 3 light-years of the Milky Way's supermassive black hole, known as Sagittarius A. The large fluctuations in these objects' brightness suggest that they are black holes and neutron stars stealing matter from companion stars. Stellar-mass black holes and neutron stars both form from the collapsed cores of stars that died in supernova explosions.
Team member Mark R. Morris, also of UCLA, theorized in 1993 that 10,000 stellar-mass black holes resided within 3 light-years of our galaxy's center. In the process he invoked, known as dynamical friction, frequent close encounters among objects fling the more massive objects toward the center of the crowded environment and less massive objects outward. During the several billion years that our galaxy has been around, Morris proposed, this effect should have caused black holes and neutron stars, which are more massive than typical stars, to migrate toward Sagittarius A.
A small fraction of these migrating objects would pair up by chance with stars near the galactic center and start pulling in matter from these accidental partners. Such transfers of matter would trigger copious X-ray emissions detectable by Chandra.
The researchers calculate that without dynamical friction, there would be only a 20 percent chance of finding one of these X-ray sources within 3 light-years of Sagittarius A. Finding four of them suggests that such objects are 20 times as common in the galaxy's inner 3 light-years as scientists would expect without the concentration effect. "This is the first evidence that [Morris'] prediction is actually true," Muno says. The researchers presented their new data on Jan. 10 in San Diego at a meeting of the American Astronomical Society The American Astronomical Society (AAS, sometimes pronounced "double-A-S") is a US society of professional astronomers and other interested individuals, headquartered in Washington, DC. .
"The objects observed by Muno are undoubtedly either stellar-mass black holes or neutron stars," says Milos Miloš, prince of Serbia
Miloš or Milosh (Miloš Obrenović) (both: mĭ`lôsh ōbrĕ`nəvĭch) Milosavljevic of the California Institute of Technology California Institute of Technology, at Pasadena, Calif.; originally for men, became coeducational in 1970; founded 1891 as Throop Polytechnic Institute; called Throop College of Technology, 1913–20. in Pasadena, who studies interactions of objects near the galaxy's center. But he says that the objects could have formed where they are rather than migrated in from farther out farther out
Of or relating to an option contract with a later expiration date than a contract that is currently owned or being considered. For example, a contract with a May expiration date is farther out than a contract with a February expiration date of .
Figuring out exactly where the black holes came from means figuring out where the short-lived, massive stars that gave birth to them originated, says Morris. He's planning to determine the motions of the current generation of such stars by making further observations that provide clues to their origins.