Natural Spectrum of the Universe?

AI Thread Summary
The discussion centers on finding a comprehensive graph of the natural spectrum of various cosmic bodies, including stars, black holes, and solar winds. Participants express interest in understanding the relative contributions of energy density from these sources, noting that starlight accounts for about 10% of the Cosmic Microwave Background (CMB) energy density. There is a debate about whether certain frequencies occur naturally, with the consensus being that they do not. The conversation highlights the importance of position in determining the perceived spectrum, as proximity to stars or galaxies influences the total flux. A desire for a graph showing relative amplitudes across the electromagnetic spectrum is emphasized as a valuable resource.
Physt
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Chronos said:
I assume you are interested in the relative contribution of energy density from all sources. For starlight, including energy absorbed and re-radiated by 'dust', it is comprises about 10% of the CMB energy density (re: http://condor.depaul.edu/asarma/Teaching/Spring2012/PHY475/LEC475/Lec8apr18.pdf).
Specifically I'm interested in knowing if there are any frequencies that don't occur naturally - though a graph of observed spectra would be a nice start.
 
Physt said:
Specifically I'm interested in knowing if there are any frequencies that don't occur naturally

There are not.
 
Vanadium 50 said:
There are not.
It would still be nice to have a graph of the spectrums seen with relative amplitudes.
 
bapowell said:
"Entire spectrum" of what?
The EM spectrum - what this post is about.
 
What part of the CMB spectrum do you find objectionable? Do you think it filters out other background contributions- like from stars and dust? If so, provide citations.
 
Physt said:
It would still be nice to have a graph of the spectrums seen with relative amplitudes.

I am sorry that I didn't do all the work that you asked me to.
 
  • #10
Physt said:
It would still be nice to have a graph of the spectrums seen with relative amplitudes.
This will depend heavily on your position. As an example: close to a star, the stellar spectrum is a good approximation for the total flux, while far away from stars (or even from galaxies) the CMB is more important. The other energy ranges depend on your position as well.
 
  • #11
Chronos said:
What part of the CMB spectrum do you find objectionable? Do you think it filters out other background contributions- like from stars and dust? If so, provide citations.
Nothing whatsoever - the issue is not having a graph of the relative amplitudes by frequency.
 
  • #12
mfb said:
This will depend heavily on your position. As an example: close to a star, the stellar spectrum is a good approximation for the total flux, while far away from stars (or even from galaxies) the CMB is more important. The other energy ranges depend on your position as well.
This is a fair point - I guess I'm just looking for the best average across the universe as far as we can tell at this point.
 
  • #13
http://www.pha.jhu.edu/~kgb/cosspec/ is one for just the visual range.
 
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