`Big Bang satellite data not flawed, say scientists

Cosmologists have said that data from a satellite robing the early universe is not flawed, despite one radio astronomers laim that it is hopelessly contaminated by radiation from our own galaxy.

London, Nov 15: Cosmologists have said that data from a satellite robing the early universe is not flawed, despite one radio astronomer's laim that it is hopelessly contaminated by radiation from our own galaxy.

The Wilkinson Microwave Anisotropy Probe (WMAP) satellite has been nvestigating the afterglow of the Big Bang, called the cosmic microwave ackground (CMB).

This radiation is extremely uniform in brightness in all directions in the ky, but the WMAP has charted tiny variations between different parts of the ky to produce a map of the radiation.

Researchers have analysed the variations in detail and used them to alculate key properties of the universe.

Gerrit Verschuur of the University of Memphis in Tennessee, a veteran radio stronomer, has said that the variations in microwave radiation were ctually caused by material in the Milkyway, so they don't reveal anything bout the early universe.

He noticed alignments between the bright patches seen by WMAP and the istribution of hydrogen in our own galaxy.

The astronomer also pointed out that there were dozens of cases where bright atches in the WMAP data were closely aligned with concentrations of ydrogen in earth's galaxy.

He, however, does not dispute that the majority of the radiation came from he early universe, but adds that small amounts of additional radiation manating from the Milkyway are causing changes in uniformity.

Cosmologists Kate Land of the University of Oxford, UK, and Ane Slosar of he Berkeley Center for Cosmological Physics in California, US, have ountered Verschuur's claim by saying they have found no statistically ignificant connection between the two.

"If the correlation he claims is true, then this would be major news," losar said.

"I would be surprised if such a big effect which Verschuur claims would scape the WMAP team anyway, but nevertheless, it is worth testing. What we ound is what is expected, that there is no correlation between these two aps," Slosar said.

Slosar added that their team tried filtering the hydrogen data in their tudy and still found only the small number of alignments expected by hance, rather than a larger, statistically significant number.

Verschuur hopes that young astronomers will take his claim seriously and urther his investigations.

The study will be posted online in the Astrophysical Journal.

ANI