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Galactic Merger question

  1. Jan 23, 2006 #1
    Hello everyone, :biggrin:
    Ok astronomers currently know that Andromeda is gonna collide with the Milky Way, i believe i read somewhere that our local group of galaxies is referred to as the "virgo cluster". what i'd like to know is:

    1) Is the collision between these two spirals gonna result in an Elliptical galaxy, or are they gonna merely jsut "brush" by each other like 2 ships in the fog (so to say)

    2) At what velocity is Andromeda heading towards the Milky Way, also does the rate of each one's velocty going to have an affect on how they merge ( i think so just wanna be sure)?

    3)Found this applet http://burro.astr.cwru.edu/JavaLab/GalCrashWeb/main.html
    using this and, based on current data is it possible to show how this collision might accour?

    Thank everyone.
    Last edited: Jan 23, 2006
  2. jcsd
  3. Jan 27, 2006 #2


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    The local group of galaxies (dominated by Andromeda and the Milky Way) is called, simply, the "Local Group". We are, in turn, a part of a much larger collection of galaxies known as the Coma-Virgo Supercluster. In addition, there is another (more compact) cluster of galaxies known as the "Virgo Cluster" and it's believed that our local group will eventually merge with this cluster.

    The galaxies are bound and dissipative forces will eventually force a collision. It will take them several passes to completely merge, however. We don't know for sure whether they will form an elliptical or not, but many believe that the collision of two large spiral galaxies (like the Milky Way and Andromeda) will lead to the formation of an elliptical galaxy. Since we can't watch galaxies collide in real time, it's hard to say for sure.

    Andromeda is approaching us at around ~250 km/s. Not only does the speed matter for the resulting collision, but also the relative orientations of the galaxy disks. If the disks are rotating in opposite directions, then the stars nearer to our galaxy will spend more time in close proximity. This leads to a "stronger" collision and more pronounced tidal tails.

    I can't load it on this computer, but I can't think of any reason why we couldn't simulate the Milky Way-Andromeda collision...except perhaps for the still large uncertainty in their dark halo masses.
  4. Mar 11, 2006 #3
    Thank you space tiger.
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