Planck unveils the Universe – old and young
05 Jul 2010
A mission to study the early Universe has delivered its first image of the entire sky – shedding light on events after the Big Bang.
The Planck satellite, a European Space Agency(ESA) project looking at the origins of our Universe partially built by scientists at The University of Manchester, have released the extraordinary picture which gives new insight into how stars and galaxies form.
From the closest portions of the Milky Way to the furthest reaches of space and time, the new all-sky Planck image is an extraordinary treasure chest of new data for astronomers.
Using microwaves, the image highlights regions of space that are likely to be where stars form and has the unique ability to separate different types of dust at temperatures of just a few to tens of degrees above absolute zero.
The different colours in the image show different components of the interstellar medium (the material between the stars in our Galaxy) including different types of gas and dust.
Astronomers at the Jodrell Bank Centre for Astrophysics helped construct parts of Planck, and the signals that it is detecting are being analysed by a team there.
Professor Richard Davis, part of the team that constructed components of Planck at the University of Manchester, said: "This image shows that our Galaxy is full of gas and dust at a whole range of temperatures, some from old stars and some forming new stars. It also shows the sort of material that formed us - and it is beautiful."
Less spectacular but perhaps more intriguing is the mottled backdrop at the top and bottom. This is the cosmic microwave background (CMB) radiation. It is the oldest light in the Universe, the remains of the fireball out of which our Universe sprang into existence 13.7 billion years ago.
While the Milky Way shows us what our local neighbourhood looks like now, those microwaves show us what the Universe looked like close to its time of creation, before there were stars or galaxies. The CMB radiation was released as the first atoms were forming, about 400 000 years after the Big Bang, and is at the heart of Planck's mission to decode what happened in the primordial Universe.
The microwave pattern is the cosmic blueprint from which today's clusters of galaxies were built. The different colours represent minute differences in the temperature and density of matter across the sky. Through the action of gravity, these small irregularities evolved into denser regions that became the galaxies of today.
The CMB covers the entire sky but most of it is hidden in this image by the Milky Way's emission, which must be digitally removed from the final data in order to see the microwave background in its entirety.
Planck looks at the sky in nine different bands, or colours, of microwave light, which have wavelengths thousands of times that of optical light. These nine different bands, ranging from frequencies of 30 to 850 GHz, are crucial for understanding which parts of the Planck data are from the early Universe, and which are from our own Galaxy.
A number of UK institutions have been involved in the design and construction of the satellite, and are now working alongside colleagues from around the world to operate the satellite and analyse the data.
When this work is completed, Planck will show us the most precise picture of the cosmic microwave background ever obtained. The big question will be whether the data will reveal the cosmic signature of the primordial period called inflation. This era is postulated to have taken place just after the Big Bang and resulted in the Universe expanding enormously in size over an extremely short period. It is a cornerstone of the standard cosmological model, and results from sensitive experiments such as Planck are required to increase our understanding of it.
Emeritus Professor Rod Davies from The University of Manchester, who is leading the work to understand the Galactic emission seen by Planck, said: “It is particularly rewarding for me to see the culmination of a 30-year involvement in Cosmic Microwave Background research beginning with radio telescopes at Jodrell Bank in Cheshire, then under the clear dry skies on the high volcanic slopes of Tenerife and finally with the construction by Jodrell Bank of the radio receivers for Planck's Low Frequency Instrument."
Notes for editors
For more information see http://www.esa.int/planck
The map is also available on Chromoscope, where it can be compared with images at other wavelength.
Jodrell Bank's role in Planck
Jodrell Bank Centre for Astrophysics (JBCA) is directly involved with the two lowest frequencies of the Low Frequency Instrument, the 30 and 44 GHz radiometers. These have 4 and 6 detectors respectively, operating at 20K (-253.15°C or -423.67°F). The resolution on the sky will be 33 and 27 arc minutes, and the sensitivity 1.6 and 2.4 micro K (1s, over 12 months). The cryogenic low noise amplifiers which are the heart of the radiometers were developed at Jodrell Bank, with help from the University of Birmingham and The Rutherford Appleton Laboratory.
Dr B. Maffei and Dr G. Pisano are involved in the other focal instrument, the HFI. First at Cardiff University and now at the University of Manchester, they have played a major role in the design, development and calibration of the Focal Plane Unit, in particular the cold optics, in collaboration with the Institut d'Astrophysique Spatiale - France, Maynooth University - Ireland and JPL/Caltech - USA.
The work to understand the Galactic emission seen by Planck is being co-lead from Jodrell Bank by Emeritus Professor Rod Davies. A number of projects are led by Jodrell Bank scientists, including Professor Richard Davis and Dr Clive Dickinson. Each of the 14 projects focusses on one aspect of the Galaxy as seen by Planck, including the electrons that gyrate in the Galactic magnetic field, the ionized gas that pervades the interstellar medium and the dust grains that emit across the entire frequency range that Planck is sensitive to. Jodrell Bank is also leading the calibration and identifying systematics in the LFI data.
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