Revealing the Cosmic Microwave Background with Planck


This animation illustrates the painstaking work performed by cosmologists in the Planck Collaboration to extract the Cosmic Microwave Background from the data collected by Planck. The first image in the sequence shows the sources of emission detected on the whole sky at the microwave and sub-millimetre wavelengths probed by Planck, which range from 11.1 mm to 0.3 mm (corresponding to frequencies between 27 GHz and 1 THz).
The different sources of emission include:
– discrete emission from individual galactic and extragalactic sources;
– diffuse radio emission from interstellar material in the Milky Way, which is mostly due to synchrotron radiation emitted by electrons that spiral along the lines of the Galactic magnetic field, but also comprises bremsstrahlung radiation, emitted by electrons that are slowed down in the presence of protons, as well as emission from spinning dust grains;
– diffuse emission due to the thermal emission from interstellar dust in the Milky Way;
– and, finally, the Cosmic Microwave Background.

The cosmologists had to remove all possible contamination due to emission by foreground sources before they could fully explore the Cosmic Microwave Background data and compare them to cosmological models.

Two CMB anomalous features hinted at by Planck’s predecessor, Nasa’s WMAP, are confirmed in the new high-precision data. One is an asymmetry in the average temperatures on opposite hemispheres of the sky (indicated by the curved line), with slightly higher average temperatures in the southern ecliptic hemisphere and slightly lower average temperatures in the northern ecliptic hemisphere. This runs counter to the prediction made by the standard model that the universe should be broadly similar in any direction we look. There is also a cold spot that extends over a patch of sky that is much larger than expected (circled). In this image the anomalous regions have been enhanced with red and blue shading to make them more clearly visible http://www.guardian.co.uk/science/picture/2013/mar/21/planck-most-detailed-map-universe-cosmic-microwave?CMP=twt_fd#zoomed-picture

Two CMB anomalous features hinted at by Planck’s predecessor, Nasa’s WMAP, are confirmed in the new high-precision data. One is an asymmetry in the average temperatures on opposite hemispheres of the sky (indicated by the curved line), with slightly higher average temperatures in the southern ecliptic hemisphere and slightly lower average temperatures in the northern ecliptic hemisphere. This runs counter to the prediction made by the standard model that the universe should be broadly similar in any direction we look. There is also a cold spot that extends over a patch of sky that is much larger than expected (circled). In this image the anomalous regions have been enhanced with red and blue shading to make them more clearly visible (guardian.co.uk)

Read more at http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=51551

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