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'Close Encounters' and Galaxy formation

  1. Jun 11, 2010 #1
    So I was reading through a textbook and came across the term 'close encounter' but no definition or explination of what it means. From what I can make out, I would assume it's refering to asteroid interaction with young galaxies and the role in forming galaxies and stars but this is all guesswork. Can anyone give me a good explination/link to an explination of what exactly 'close encounters' refers to/means.

  2. jcsd
  3. Jun 11, 2010 #2


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    I think we'd need the phrase in context.
  4. Jun 11, 2010 #3
    Ok, I can't find the page again, but it read something along the lines of "random close encounters play a much greater role in the evolution of galaxies than stars". I was trying to work it out, but would rather have someone who knows what it means help!
  5. Jun 11, 2010 #4


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    Sounds like they're talking about random close encounters between neighbouring galaxies.

    (Asteroids will not play a role in galaxy formation.)

    Ah. Evolution, not creation. Missed that.

    Yes, they are surely talking about random close encounters between galaxies. Look at differences between spherical galaxies and spiral galaxies.
  6. Jun 11, 2010 #5
    I'm not sure I understand. How can the close encounters of galaxies cause the creation of different typed galaxies.

    As a guess, I'd think that maybe the close encounters will cause the slowing of (any) rotation and so elliptical galaxies.
  7. Jun 11, 2010 #6


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    Spiral galaxies are finely detailed. This cannot occur if they're being buffeted all the time. Close encounters tend to turn spirals into sphericals. Sphericals tend to flatten into spirals if given lots of time.

    Wiki has some stuff on galactic evolution.
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