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Dark Matter - How strong is it at a galaxy periphery?

  1. Jul 9, 2012 #1
    How strong is the influence of dark matter typically at the periphery (50.000 LY away from the center) for example in the Milky Way

    I mean is the Acceleration Due to Gravity (due to dark matter) (typically) 80% - 85% - 90% - 95 % - or 97% stronger as the Acceleration Due to Gravity caused by visible matter.
  2. jcsd
  3. Jul 10, 2012 #2


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    Staff: Mentor

    Here is a website I found which discusses this. v^2 is proportional to the mass inside divided by the radius, and the mass inside is proportinal to the gravitational force and the stars acceleration due to gravity.
    1pc = 3,3 ly.

    Compared to the Milky Way, other galaxies are easier to observe, but I think the situation is similar here. At ~50kly, dark and visible matter have a similar influence, further away from the center dark matter dominates - the presented fit indicates a distribution of 25%/75% at 50kpc.
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