Home
- Planck satellite picks up beams of radiation from centre of Milky Way which could prove existence of 'dark matter'
- Researchers at Niels Bohr Institute say radiation is either proof - or something currently unknown to physics
By Eddie Wrenn
PUBLISHED:04:03 EST, 5 September 2012| UPDATED:04:03 EST, 5 September 2012
Scientists believe they are on the verge of solving the 70-year-old mystery of dark matter.
The structure of the observable universe suggests there is a lot of matter that we simply cannot see, and astronomers, cosmologists and particle physicists have been looking for answers to what it could be.
But now the ESA Planck satellite has picked up radiation beams from the centre of the Milky Way, and scientists believe they have discovered proof that dark mater exists - otherwise the alternative would re-write physics as we know it.
Pavel Naselsky, professor of cosmology at the Niels Bohr Institute at the University of Copenhagen, said: '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 centre.'
Radiation map of the skies: A false colour image of the whole sky as seen by Planck, the space observatory
WHAT THE IMAGE ABOVE TELLS US
In this image, the dust of the Milky Way is shown in blue, with a red band across the centre showing hot regions.
The mottled yellow area above and below represents relic radiation, otherwise known as the Cosmic Microwave Background, created in the fireball of the Big Bang 13.7 billion years ago, which is the oldest light in the Universe.
Such an image allows scientists to study both the origins of the Universe and the birth of stars in our galaxy.
Researchers were studying data from the Planck satellite, launched in 2009.
The satellite does not just remain still in space, but changes direction every hour as well as rotates once a minute on its own axis.
These movements mean that it scans the entire surrounding Universe in the course of six months, using extremely sensitive instruments that can map microwave radiation in the entire sky with great precision.
The latest data from the Planck mission reveals unusual radiation from our own galaxy, which open a new direction in understanding the most fundamental properties of the space, time and matter in the Universe.
Naselsky said: 'We have observed a very unique emission of radio radiation from the centre 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 - electrons and positrons circulating at high energies around the lines of the Magnetic Field in the centre of the galaxy, and there are quite strong indications that it could come from dark matter.'
Planck produced its first all-sky image in 2010, and scientists are currently working to analyse and parse the various and complex elements
Naselsky said that leading scientists like Niels Bohr professor Subir Sarkar have predicted, using calculations, 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 also usually very scattered and do not interact with each other.
'But we know from theoretical predictions that the concentration of dark matter particles around the centre 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 centre of the galaxy and in doing so produce this very unusual synchrotron radiation.
It has simply not been possible to observe this radiation in such detail before, as previous instruments have not been sensitive enough. But with Planck, this unusual radiation is seen very clearly.'
The results have been published in ArXive.org. and submitted to the scientific journal, Astronomy and Astrophysics.
