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Question about galaxies

  1. May 28, 2004 #1
    Galaxies are all relatively the same size, ranging from a few thousand light years in diameter, to a hundred thousand light years or so. There seems to be some factors involved as to how large they can become, although I’m not sure it has anything to do with mass?
    Can someone please explain galaxy formation and more specifically what contributing factors play a role in their actual sizes?
  2. jcsd
  3. May 28, 2004 #2


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    These would be a thorough start.


    http://origins.stsci.edu/under/galaxies.shtml [Broken]


    Last edited by a moderator: May 1, 2017
  4. May 28, 2004 #3
    Some very helpful links Labguy!

    So over a time scale of about 10 billion years our galaxy should form around 30 or 40 billion stars, not to mention recent observation of increased star production in early galaxies.
    This and occasional collisions and cannibalism, contribute to galaxies of ever increasing sizes. But why is it we don’t see galaxies on the really enormous scales?

    Would it be possible that gravitational strengths influence the relative size of a galaxy? The bulk or the core of a galaxy acting similarly to a sun in a solar system, the combined gravitational force can only capture a certain number of stars, so even when mergers do occur, a galaxy can’t just keep adding to it’s mass exponentially?
  5. May 30, 2004 #4
    This kind of surprised me!

    http://curious.astro.cornell.edu/question.php?number=412 [Broken]
    Last edited by a moderator: May 1, 2017
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