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Significance Maps Question

  1. Jun 16, 2014 #1
    Dear All,

    I have a question regarding the understanding of anisotropy of cosmic rays and how to understand them better. To determine the anisotropy I have seen a lot of papers where they use maps that have a Relative Intensity map and a Statistical significance map of the sky.

    I understand the relative intensity map, but I don't understand why the statistical significance maps are used, could some one explain this to me?


  2. jcsd
  3. Jun 16, 2014 #2


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    Hmmm... do you happen to have a link to one of the maps?
  4. Jun 17, 2014 #3
    Sure, here is a paper that I have been recently reading.
    It's figure 3 at page 15.
    At section 3.2, they are explained but I don't really understand it yet, they say that they use the Li and Ma paper:
    http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1983ApJ...272..317L&defaultprint=YES&filetype=.pdf [Broken]
    Last edited by a moderator: May 6, 2017
  5. Jun 17, 2014 #4


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    I'm actually not certain. At first glance I would think that the significance level depends on the intensity of the radiation and the observation time, with a higher significance corresponding to a higher chance that the signal is real and not a background fluctuation, but I'm not sure why the significance level goes into the negative.
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