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The all-sky map released now is based on the first 15.5 months of
observations with the Planck space telescope, a mission of the
European Space Agency (ESA), and shows the oldest light in the
universe. This was emitted when the universe was only 380,000 years
old and became transparent for the first time after the Big Bang. The
"primordial soup" of protons, electrons and photons cooled gradually,
allowing neutral hydrogen atoms to form and the light to escape. As
the universe continued to expand and to cool, this radiation was
shifted to longer wavelengths, so that it is received today as the
cosmic microwave background (CMB) at a temperature of about 2.7
Kelvin.
Tiny temperature fluctuations in this CMB map reflect smallest density
fluctuations in the early universe. "The Planck CMB map provides us
with an extremely detailed picture of the very early universe," said
Simon White, Co-Investigator in the Planck Collaboration and director
at the Max Planck Institute for Astrophysics (MPA), who helped to
establish the standard model of cosmology in the 1980s by analysing
the evolution of structure in the universe. “All the structures that
we see today grew from tiny density fluctuations shortly after the Big
Bang.”
Planck was designed to measure these fluctuations across the whole sky
with greater resolution and sensitivity than ever before, allowing
scientists to determine the composition and evolution of the universe
from its birth to the present day.
"The Planck data fit extremely well with the standard model of
cosmology," says Torsten Ensslin, who is managing Germany's
participation in the Planck mission at MPA. "The cosmological parameters have
been refined with Planck more accurately than ever, and our analysis
passed all tests against various other astronomical observations with
flying colours."
The analysis of the Planck data show that normal matter, making up
galaxies, stars and also Earth, contribute only about 4.9% to the mass
and energy density of the universe. About 26.8% is dark matter, which
interacts only through its gravitational effect – contributing far
more than previously assumed. Dark energy, the mysterious component
that causes the universe to expand ever faster, on the other hand,
accounts for only 68.3%, less than expected. Finally, the Planck data
also set a new value for the rate at which the Universe is expanding
today, known as the Hubble constant. At 67.15 km/s/Mpc, this is
significantly less than the current standard value in astronomy. The
data imply that the age of the Universe is 13.82 billion years.
However, because the precision of Planck’s map is so high, it also
revealed some peculiar unexplained features, which cannot easily be
reconciled with the standard model. One of the most surprising
findings is that the fluctuations in the CMB temperatures at large
angular scales are not as strong as expected from the smaller scale
structure revealed by Planck. Another is an asymmetry in the average
temperatures on opposite hemispheres of the sky. This runs counter to
the prediction made by the standard model that the Universe should be
broadly similar in any direction we look. Furthermore, a cold spot
extends over a patch of sky that is much larger than expected. This
data could point to an extension of the standard model or even new
theories.
“But even if we do not yet understand these anomalies, we can
eliminate the possibility that they are due to foreground effects,”
says Torsten Ensslin. “The ‘cold spot’, in particular, has been known
for quite a while and could well be a statistical fluctuation.”
The MPA scientists have been involved in software development even
from before the beginning of the mission, to process the data and
remove foreground emission from objects such as galaxies, quasars, and
even our own Milky Way. By now, their work focuses on analysing
information from the cosmic microwave background radiation and trying
to better understand our universe.
One aspect, amongst many others, is the discovery and measurement of
galaxy clusters by the Sunyaev-Zel'dovich effect. The SZ effect is a
characteristic signature imprinted by galaxy clusters on the cosmic
microwave background, when the light from the CMB passes through the
cluster. Because of the different frequency bands available with
Planck, the SZ effect can be used as a unique tool for detecting
galaxy clusters.
Rashid Sunyaev, Co-Investigator in the Planck Collaboration and
director at the Max Planck Institute for Astrophysics, together with
Yakov Zel'dovich predicted not only the effect of galaxy clusters on
the CMB but also the existence of the acoustic peaks in the CMB itself
which Planck has now measured so precisely. He is excited by the
Planck results: "When we developed our models of the CMB radiation
more than 40 years ago, we thought of it mainly as a theoretical
thought experiment. It is amazing that the measurements are now so
detailed that it can even be used as tool to discover hundreds of new
galaxy clusters that where unknown before. A great success for
Planck!”
Planck scientists were even able to use this sample of clusters of
galaxies to derive key parameters of the universe – a method that has
been employed with CMB data for the first time. This is an additional
and completely independent method from the way which uses the shape and
amplitude of the acoustic peaks.
For more information:
The new data from Planck are based on the first 15.5 months of its all-
sky surveys, about half of the data expected from the mission overall.
Launched in 2009, Planck was designed to map the sky in nine
frequencies using two state-of-the-art instruments: the Low Frequency
Instrument (LFI), which includes the frequency bands 30–70 GHz, and
the High Frequency Instrument (HFI), which includes the frequency bands
100–857 GHz. HFI completed its survey in January 2012, while LFI
continues to operate.
Planck’s first all-sky image was released in 2010 and the first
scientific data were released in 2011. Since then, scientists have
been extracting the foreground emissions that lie between us and the
Universe’s first light to reveal the CMB presented in this release.
The next set of cosmology data will be released in early 2014.
The Planck Scientific Collaboration consists of all the scientists who
have contributed to the development of the Planck mission, and who
participate in the scientific exploitation of the Planck data during
the proprietary period. These scientists are members of one or more of
four consortia: the LFI Consortium, the HFI Consortium, the DK-Planck
Consortium, and ESA's Planck Science Office. The two European-led
Planck Data Processing Centres are located in Paris, France and
Trieste, Italy.
German participation in the Planck mission is based at the Max Planck
Institute for Astrophysics (MPA), as Rashid Sunyaev and Simon White
are the German co-Investigators in the two instrument consortia. It is
funded by the German national aeronautics and space research centre
DLR and the Max Planck Society (MPG). MPA and MPG support the
scientific participation in the mission, DLR the majority of the
technical contribution, especially the MPA Planck Analysis Centre
(MPAC).
The MPAC is responsible for providing data analysis infrastructure for
data centres and for the individual Planck scientists. Within the IDIS
data system of Planck (Integrated Data and Information System), the
MPAC is responsible for both the provision of a workflow engine and a
data management component and also has to provide development,
integration and operation of the data simulation pipeline.
Link:
An explanation of the cosmic microwave background radiation can be found
in a comic, which was created in 2009:
 Riding early waves
Contact:
Dr. Torsten Enßlin
Max-Planck-Institut für Astrophysik
Tel. 089 30000-2243
E-mail: tensslin mpa-garching.mpg.de
Dr. Hannelore Hämmerle
Pressesprecherin
Max-Planck-Institut für Astrophysik
und Max-Planck-Institut für extraterrestrische Physik
Tel. 089 30000-3980
E-mail: prmpa-garching.mpg.de
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