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A Galaxy mass distribution without DM

  1. Jul 15, 2016 #1
    I've searched for a formula of galaxy mass Distribution formula along the radius, often the papers say:
    ρ∝ex
    ( ρ is the surface density, x is distance from the Center of the galaxy). is it correct without DM?
    Or is there any other correct formula?
     
  2. jcsd
  3. Jul 15, 2016 #2

    mfb

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    Staff: Mentor

    What do you mean by "correct without DM"? Without DM, the galaxies as we know them would not exist.
     
  4. Jul 15, 2016 #3
    I'd like to know the mass distribution without dark matter, estimated by only visible mass.
     
  5. Jul 15, 2016 #4

    mfb

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    If the paper is talking about a surface density, I would expect that to be limited to the visible mass contribution. Dark matter doesn't form a nice disk.

    The exponential shape is odd, by the way, it has to have a limited range.
     
  6. Jul 17, 2016 #5
    That means the surface density is only about the visible mass contribution.
    I should have a look again. Thanks!
     
  7. Sep 1, 2016 #6

    ohwilleke

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    There shouldn't be just one formula. The mass distribution in galaxies differs materially between, for example, elliptical galaxies, disk galaxies with bulges, disk galaxies without bulges, dwarf galaxies, etc.
     
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