Wilkinson Microwave Anisotropy Probe

Nov 14, 2007 15:07 GMT  ·  By

Data collected by the Wilkinson Microwave Anisotropy Probe or WMPA is not flawed, but rather contaminated with radio radiation coming from our galaxy. The WMPA is a satellite, launched in 2001 by NASA, to probe the Cosmic Microwave Background or CMB, and find minute differences of temperature to test certain theories about the nature of our universe. The CMB is a remnant of the afterglow of the universe produced 380,000 years after the Big Bang, when the matter was hot and glowing.

Though the radiation coming from all directions of the universe is extremely bright, the WMPA has charted tiny variations in different parts of the sky to produce a map of the early universe with the help of the radiation. This data can be further analyzed to determine certain properties, such as the ratio between the ordinary matter and the invisible dark matter, if any exists.

However some radio astronomers say that the observed variations in the CMB are not from the early universe, but actually come from matter inside our galaxy, detected by aligning the bright patches of radiations seen by the WMPA, with the distribution of matter in the galaxy, so the background radiation cannot give us too much information about the early universe, because it is contaminated by other sources of radiation.

The map of the distribution of matter in our galaxy was completed in 2005, through a project called the Leiden-Argentina-Bonn (LAB) survey, as well as the Leiden-Dwingeloo survey completed in 1997, by using ground radio telescopes to observe the radio emission from the hydrogen.

Gerrit Verschuur of the University of Memphis in Tennessee, US, does not dispute that the majority of the CMB radiation is from the early universe, but says that small amounts of radiation come from sources inside our galaxy and are probably causing many of the apparent variations from uniformity. The brightest patches seen by the WMAP are suspected to actually be spots of plasma, created by hydrogen filaments colliding inside the galaxy.

The statistical correlation between the two maps showed no obvious connection between the two, according to cosmologists who are not on the WMAP team. But Vershuur believes that the statistical method is incorrect and if data were filtered to show moving hydrogen only in the specific velocity ranges, the connection between the colliding hydrogen and the WMAP bright spots would be clearer.

The team that made the statistical calculations says that they already tried the filtering method, but only found a number of filaments, which corresponds to statistical chance, meaning the data is inconclusive and the connection between the two maps cannot be done.

The scientific community, on the other hand says that the data observed in the WMAP mission point that the properties of the universe are also confirmed by using alternative methods.

Verchuur says he is not surprised that he could not convince anybody that he is right, but he still has hopes that the young astronomers will take his work seriously.

Photo Gallery (2 Images)

Image of the earlyest galaxies, obtained by gravitational lensing
Image of the matter distribution 380,000 years after the big bang
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