martes, 27 de septiembre de 2011
Stars Signal Existence of Dark-Matter Objects --"Primordial Black Holes"
Scientists may be able to spot evidence of elusive dark matter by detecting vibrations on the surfaces of stars that could indicate that a dark-matter object known as a primordial black hole has passed through the stars, according to the study. The ripples could thus provide observable proof of dark matter, which is thought to make up more than 80 percent of all matter in the universe but has thus far evaded direct detection.
"There's a larger question of what constitutes dark matter, and if a primordial black hole were found it would fit all the parameters," study co-author Shravan Hanasoge of Princeton University said in a statement. "Identifying one would have profound implications for our understanding of the early universe and dark matter."
The new study could help scientists get a better handle on what dark matter is, researchers said. They simulated what would happen if a primordial black hole passes through a star.
Primordial black holes are theoretical remnants of the Big Bang, the explosive event that created the universe. These odd objects, which have yet to be observed, are one of various cosmic structures that may be the source of dark matter, researchers said.
Primordial black holes are much smaller than "normal" black holes and thus would not swallow up a star and all of its light. Rather, their collisions with stars would cause noticeable vibrations on the stars' surfaces.
"If you imagine poking a water balloon and watching the water ripple inside, that's similar to how a star's surface appears," said lead author Michael Kesden of New York University. "By looking at how a star's surface moves, you can figure out what's going on inside. If a black hole goes through, you can see the surface vibrate."
"Now that we know primordial black holes can produce detectable vibrations in stars, we could try to look at a larger sample of stars than just our own sun," Kesden added. "The Milky Way has 100 billion stars, so about 10,000 detectable events should be happening every year in our galaxy if we just knew where to look."
Physical Review Letters & space.com
Source: The Daily Galaxy