Astronomers found Gaping hole in universe

Group of astronomers have found a giant 'hole' in the universe that measures nearly a billion light-year across. The large galactic void is empty of galaxies, stars, dust clouds and, oddly enough, even dark matter. The discovery has left scientists clambering for a plausible explanation, however, as of right now one hasn't arisen. Scientists claim that a galactic void this large is far from a normal occurrence.

The region was intially discovered by NASA's Wilkinson Microwave Anisotropy Probe (WMAP) Satellite. At that time, scientists had no idea that it would turn out to be a giant space void.

The astronomers said the region even appeared to lack dark matter, which cannot be seen directly but is usually detected by measuring gravitational forces. The void is in a region of sky in the constellation Eridanus, southwest of Orion. The team at the University of Minnesota said the void is nearly a billion light-years across and they have no idea why it is there.

"Not only has no one ever found a void this big, but we never even expected to find one this size," said astronomy professor Lawrence Rudnick.

Writing in the Astrophysical Journal, Rudnick and colleagues Shea Brown and Liliya Williams said they were examining a cold spot using the Wilkinson Microwave Anisotropy Probe satellite, and found the giant hole.

"We already knew there was something different about this spot in the sky," Rudnick said. The region stood out as being colder in a survey of the Cosmic Microwave Background -- the faint radio buzz left over from the Big Bang that gave birth to the Universe.

"What we've found is not normal, based on either observational studies or on computer simulations of the large-scale evolution of the Universe," Williams said in a statement.

The WMAP satellite measures the temperature of cosmic microwave background radiation (CMB) over the entire sky. CMB radiation is a form of electromagnetic radiation that fills the entire universe and can be detected in all regions of space. This radiation is remnant heat from the Big Bang and is very cold, measuring just 2.725° above absolute zero.

On the map of the Cosmic Microwave Background (CMB) radiation produced by the WMAP satellite, the void came up as a cold spot. Since the temperature of CMB radiation is quite uniform in all of space, scientists already knew there was something special about the region. Lead researcher Lawrence Rudnick of the University of Minnesota said "we already knew there was something different about this spot." Due to its cooler appearance on the CMB Map, the void was dubbed the "WMAP Cold Spot."

Further inspection of the hole was made using the Very Large Array (VLA) radio telescope funded by the National Science Foundation, after which it was discovered by University of Minnesota researchers that the cold spot is devoid of nearly all forms of matter. Many galactic voids exist in space, however, the WMAP Cold Spot Void is an especially unique occurrence considering that it is nearly 1,000 times larger than any other observed void. Rudnick refers to the results as "suprising."

Also involved in the research of the region was Associate Professor Liliya Williams, who stated, "What we’ve found is not normal, based on either observational studies or on computer simulations of the large-scale evolution of the Universe".


Source : DailyTech , Reuters

Categories: Astronomy