Cosmic dance challenges our understanding of the universe

A quick post today to follow-up my previous Andromeda post. I've published an article in The Conversation titled Cosmic dance challenges our understanding of the universe which describes the result. I've covered most of this in the previous post, but a slightly different spin. Enjoy.
Location: Sydney NSW, Australia

Comments

  1. Anonymous15 January 2013 at 08:23

    Geraint, I hope I'm understanding this correctly. Is the main "surprise" in this research, that the dwarf galaxies are rotating toward and away from us? If this is correct, wouldn't any object large or small that becomes part of a greater entity (a galaxy)be held by gravity and therefore orbit around the core, in varying distances?

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    Replies
    1. Cusp15 January 2013 at 08:44

      Hi John - the surprise is that there is ordered rotation in the population, so this subset of dwarfs is orbiting like the planets of the solar system, rather than the long-term comets, which are at any angle. The latter is what we would expect for the dwarf population.

      Delete
  2. Anonymous15 January 2013 at 09:00

    Are they orbiting an "unseen" centre?..or are they orbiting each other (in a planetary motion) due to the gravitational effect they have on each other?

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    Replies
    1. Cusp15 January 2013 at 11:38

      The main force the dwarf will feel will be from the Andromeda galaxy, and the dark matter halo in which they reside. The force from each other is relatively small, unless they get close together.

      Delete

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