RR Edwards Posted March 20, 2014 Share Posted March 20, 2014 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. Any opinions or arguments? http://en.wikipedia.org/wiki/Cosmic_background_radiation Link to comment Share on other sites More sharing options...
swansont Posted March 20, 2014 Share Posted March 20, 2014 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. Link to comment Share on other sites More sharing options...
RR Edwards Posted March 21, 2014 Author Share Posted March 21, 2014 So not all red shifted? I thought it should all be red shifted. Link to comment Share on other sites More sharing options...
LaurieAG Posted March 21, 2014 Share Posted March 21, 2014 All the removed emissions from our galaxy appear to be red shifted though. Link to comment Share on other sites More sharing options...
swansont Posted March 21, 2014 Share Posted March 21, 2014 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. Link to comment Share on other sites More sharing options...
Spyman Posted March 21, 2014 Share Posted March 21, 2014 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. http://lambda.gsfc.nasa.gov/product/cobe/dmr_image.cfm Link to comment Share on other sites More sharing options...
Enthalpy Posted March 21, 2014 Share Posted March 21, 2014 I understand the colours represent radiation intensity. Our Galaxy makes noises which add to the cosmological background. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now