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Planck unveils first
science results

DR EMILY BALDWIN
ASTRONOMY NOW
Posted: 11 January 2011


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The first data catalogue from ESA's Planck mission was released today highlighting the coldest objects in the Universe.


The Early Release Compact Source Catalogue contains over 15,000 individual sources of stars and galaxies. The size of the spots in the image reflects the brightness of the source. Image: ESA/Planck Collaboration.

ESA released Planck's first full-sky map last July, but now the first scientific results have been released to the astronomical community for scientists to use in their research. The Early Release Compact Source Catalogue is the first step towards Planck's key goal of tracing the formation of the very first structures in the Universe that are imprinted on the Cosmic Microwave Background (CMB) radiation, which marks the decoupling of matter and radiation 380,000 years after the big bang.

"In order to get to the final objective of Planck, to see the Universe's first light, we have to first understand everything in between," explained ESA's Jan Tauber in today's press conference where the results were announced. That means removing the signatures of all other objects in the foreground, everything from inside our own Milky Way Galaxy to stars and galaxies located outside of our Galaxy, and the Compact Source Catalogue released today already includes some 15,000 sources from such objects.


Six fields used to detect and study and Cosmic Infrared Background. Image: ESA/Planck Collaboration.

The data also reveals nearly 200 distant clusters of galaxies, including 20 previously unknown clusters, that were seen in the data as shadows against the CMB. "Planck has revealed that some of these massive clusters are still forming," said Nabila Aghanim of the CNRS-Universitie Paris Sud. "They are still merging and still assembling matter. We are also discovering rare supercluster systems, gatherings of clusters, which Planck will study in detail."

A Cosmic Infrared Background map plotting the radiation stemming from the birth of galaxies and stars, which is absorbed and re-emitted by dust in the Universe, was discussed by Jean-Loup Puget of CNRS-Universitie Paris Sud. He explained that the lowest frequency maps at 217 gigahertz show that the most distant structure formed less than two billion years after the big bang – the first time these early large structures have been imaged.

Clive Dickinson from the University of Manchester also announced further insight into the so-called Anomalous Microwave Emission (AME), a diffuse glow associated with dusty regions of our Galaxy. Until now its origin was unknown, but the Planck data confirms a theory that rapidly spinning dust grains colliding with fast-moving atoms or ultraviolet light are the cause. This is the first detailed look of this component of the interstellar medium and will help scientist remove the local microwave 'fog' from the CMBR.

Planck will continue to survey the Universe, with the final detailed view of the CMB revealed in two year's time.