Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Spectral index

  1. Apr 27, 2008 #1

    Can anybody please explain to me (in everyday language) what spectral index is? The wikipedia entry doesn't shed much light, and a lot of the textbooks give very convoluted explanations for its derivation.

  2. jcsd
  3. Apr 28, 2008 #2
    In radio terms (in my experience), spectral index applies to synchrotron sources which have brightness, S, which changes with for different frequencies, [tex]\nu[/tex], such that [tex]S \propto \nu^{\alpha}[/tex]. For a negative [tex]\alpha[/tex] this means that when a synchrotron source is observed at higher frequencies, it will be fainter. The opposite is true for positive [tex]\alpha[/tex].
    Last edited: Apr 28, 2008
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook