September 5, 2012
Planck – Solving The Dark Matter Mystery
April Flowers for redOrbit.com - Your Universe Online
Dark matter comprises a large portion of the Universe, filling the space between galaxies and stars. Since the prediction of dark matter some 70 years ago, researchers from a myriad of disciplines — astronomers, cosmologists, and even particle physicists — have been looking for answers to what dark matter could be.New observations from the Planck satellite may bring researchers from the Niels Bohr Institute closer than ever to a solution of the origin of the mysterious dark matter.
The Planck satellite, launched in 2009 by the European Space Agency (ESA), has extremely sensitive instruments onboard that can map microwave radiation in the entire sky with great precision. The main goal of this mission is to study the Cosmic Microwave Background (CMB) — the relic radiation from the Big Bang — and measure tiny fluctuations in the CMB to provide the sharpest picture ever of the early Universe.
This newest data from the Planck mission reveals unusual radiation from our own galaxy, which opens a new direction for understanding the most fundamental properties of the space, time and matter in the Universe.
“We have observed a very unique emission of radio radiation from the center of our galaxy, the Milky Way. By using different methods to separate the signal for very broad range of wavelengths, we have been able to determine the spectrum of the radiation. The radiation originates from synchrotron emission, i.e. electrons and positrons circulating at high energies around the lines of the Magnetic Field in the center of the galaxy, and there are quite strong indications that it could come from dark matter,” explains Pavel Naselsky, professor of cosmology at the Discovery Center at the Niels Bohr Institute at the University of Copenhagen.
Scientists at the Niels Bohr Institute have predicted that dark matter may consist of very heavy particles that are around 10 times as heavy as the Higgs particle, that is to say, 1,000 times heavier than a proton. But they have very unique properties and do not interact with "normal" matter particles. Dark matter particles are very scattered and do not interact with each other.
“But we know from theoretical predictions that the concentration of dark matter particles around the center of galaxies is very high and we have a strong argument they can collide there and in the collision electrons and positrons are formed. These electrons and positrons start to rotate around the magnetic field at the center of the galaxy and in doing so produce this very unusual synchrotron radiation," states Naselsky.
Before this point, it was not possible to observe this radiation in such detail, as previous instruments have not been sensitive enough. With Planck, however, this unusual radiation becomes quite clear.
“The radiation cannot be explained by the structural mechanisms in the galaxy and it cannot be radiation from supernova explosions. We believe that this could be proof of dark matter. Otherwise, we have discovered absolutely new (and unknown for physics) mechanism of acceleration of particles in the Galactic center”, says Naselsky, and he expects exciting new results already within the next few months.