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Corrections to the Cosmic background radiation map?


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In the following snippet from the Wikipedia article on Cosmic Background radiation, there is an original foto of the radiation spectrum followed by two corrected versions. In one sense they are corrected for movement, but they are also corrected for "dipole term".

It looks like they are saying "our" dipole term, if so I don't understand their meaning. From the foto itself though it seems to mean to me that they are referring to the dipole term of the early universe, as if its a given the early universe is a dipole and they are correcting by removing that dominant feature.

 

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Our (peculiar velocity) movement is the dipole term, since part of the sky will be blueshifted and part redshifted. The removal gives the middle picture. The bottom one also removes the emission from our galaxy.

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So not all red shifted? I thought it should all be red shifted.

 

It's relative. Moving toward a source will blue shift the light. All that means is it's been shifted to a higher frequency. That makes no claim to whether the expansion redshift is bigger or smaller and what the overall effect is.

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The images show temperature with the color scheme exaggerated and centered around an average temperature.

(Redshifted light have increased wavelength which is equivalent to lower energy.)

 

The following image just shows the reduced map (i.e., both the dipole and Galactic emission subtracted). The cosmic microwave background fluctuations are extremely faint, only one part in 100,000 compared to the 2.73 degree Kelvin average temperature of the radiation field.

cmb_flux.gif

http://lambda.gsfc.nasa.gov/product/cobe/dmr_image.cfm

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