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Stargazing Giant Magellan Telescope

  1. Dec 16, 2004 #1
    I hope that this monster can be able to see the Population III stars and who knows, perhaps also the last scattering surface?
  2. jcsd
  3. Dec 17, 2004 #2


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    meteor the last scattering surface is at around z = 1100, is it not?
    am I missing something?
    isn't the Magellan an optical telescope----visible light.

    so what kind of signal would be coming from the last scattering surface
    that Magellan would pick up?

    Oh, maybe I see what you mean.
    an Xray object which happens to be at the same distance as the LSS.
    I personally can not think of any Xray object that might have existed that long ago, when the universe was 300,000 years old.
    But suppose one existed (long before stars and galaxies condensed)
    and sent us some Xray light----from z=1000---and that light was redshifted by a factor of 1000 and became visible light and was received by Magellan.

    then Magellan would be seeing some Xray object at the same distance as the LSS of the CMB.

    but it is a stretch for me to imagine. maybe you can clarify, if you can imamgine it more concretely than this
    Last edited: Dec 17, 2004
  4. Dec 17, 2004 #3


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    Any such object at the LSS would have caused far greater anisotropies in the CMB than at 1 part in 105 that COBE and WMAP have observed.

    Actually we do see the LSS, it is in the microwave part of the spectrum and called the CMB!

  5. Dec 17, 2004 #4


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    But it is indeed an interesting question where the limit for visual observation is located. As soon as one enters the dark age (may be z > 10) the spectrum of the sources should have enough absobtion lines due to neutral hidrogen at different redshifts (Gunn-Peterson effect). I wonder whether it is possible to make a reasonable calculation of the limit at which visual observation will be almost impossible.
  6. Dec 17, 2004 #5
    Yes marcus, I was thinking in some kind of object that could exist at that distance. It should be an X-Ray object, as you say. The possibilities of such an object existing are very low, in fact the first stars formed 200 million of years after BB. But who knows? Maybe is possible to find such an object at that distances, for example a mini-black hole? Or a black hole of intermediate size formed by the merging of mini-black holes? It would be interesting to see such a thing
    Last edited: Dec 17, 2004
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