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Dark Matter in Milky Way

  1. Sep 8, 2015 #1
    Is the presence of Dark Matter noted in Milky Way or somewhere around solar system??
  2. jcsd
  3. Sep 8, 2015 #2


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    I remember seeing (sorry, no citation) something about our solar system having a paucity of dark matter relative to what was believe to be likely. The milky way, as far as I know, is a normal galaxy and has about 80% dark matter, 20% boronic matter just like other galaxies.
  4. Sep 8, 2015 #3


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    I believe you meant 20% baryonic matter
  5. Sep 8, 2015 #4


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    Knowing me, I probably meant moronic. :smile:
  6. Sep 10, 2015 #5
    If it didn't then it would've probably could not have held together also considering that the Milky Way can be small compared to other galaxies, so the answer to that would possibly be yes, or else it wouldn't hold together.
  7. Sep 10, 2015 #6


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    The best credible recent calculation for dark matter mass in the solar system appears to be http://arxiv.org/abs/1306.5534, Constraints on Dark Matter in the Solar System, where it is asserted "The dark matter mass in the sphere within Saturn's orbit should be less than 1.7 × 10-10 M ⊙ even if its possible concentration is taken into account." To put this into perspective Earth's mass is about 3 × 10-6 M ⊙,
  8. Sep 14, 2015 #7
    Dark matter cannot form clumps (density inhomogeneities) the size of the solar system - average velocity of DM particles is too large for that.

    We know that because if DM would be capable of doing that, the galaxy would look very different. For one, we'd see a large number of multiple star systems with "unseen mass" (IOW: systems where stars orbit way too fast). At least several percent of all multiple systems would show such effect. This is not observed.
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