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Challenging our understanding of the Universe

21 March 2013

The cosmic microwave background sky as seen by the Planck observatory.

The European Space Agency’s Planck mission with the support of University astronomers has compiled the most detailed map ever created of the cosmic microwave background (the relic radiation from the Big Bang).

The new map refines our understanding of the Universe’s composition and evolution, and unveils new features that could challenge the foundations of our current understanding of its evolution.

The image is based on the initial 15.5 months of data from Planck and is the mission’s first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380,000 years old.

This cosmic microwave background (CMB) shows tiny temperature fluctuations that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today.

Overall, the information extracted from Planck’s new map provides an excellent confirmation of the standard model of cosmology at an unprecedented accuracy, setting a new benchmark for our knowledge of the contents of the Universe.

Cardiff University researchers, led by Professor Peter Ade in the School of Physics and Astronomy, have been heavily involved in the design, build, testing and operation of the high frequency instrument on the Planck Space Telescope for over 15 years. Speaking about these new developments Professor Ade said: "Today’s news is testament to the expertise of the
scientific and technical teams who designed, built and operated Planck and its scientific instruments.

""As one of the original proposers of the Planck HF instrument 21 years ago it is fantastic to at last start to see the results of our labours. At Cardiff University we were responsible for the design and build of the cryogenic detectors at the heart of this instrument which has provided the unparalleled sensitivities we see in the 9 frequency band all-sky maps.

"With this data we are able to measure the cosmological parameters to high accuracy and thus identify small anomalies which suggest new ideas are required to explain the true nature of our
Universe. It’s truly a ground breaking mission."

The Planck data has also set a new value for the rate at which the Universe is expanding today, known as the Hubble constant. At 67.3 km/s/Mpc, this is significantly different from the value measured from relatively nearby galaxies. This somewhat slower expansion implies that the Universe is also a little older than previously thought, at 13.8 billion years.

The analysis also gives strong support for theories of "inflation", a very brief but crucial early phase during the first tiny fraction of a second of the Universe’s existence. As well as explaining many properties of the Universe as a whole, this initial expansion caused the ripples in the CMB that we see today.

Dr Locke Spencer, School of Physics and Astronomy, and member of the Planck collaboration added: "It is really exciting to be part of a project investigating such fundamental aspects of our Universe.  

"Experiments of this scale require experts across many fields and different areas of expertise at different stages of development.  It is very rewarding to see it all come together at this time as results are released to the scientific community and to the public."

School of Physics and Astronomy

Planck