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GEMS - a rich trove of information about galaxy evolution

  1. Jan 13, 2004 #1


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    A newly released mosaic image from Hubble, with 4 billion pixels, covering a square of sky about 1/2o wide, with an angular resolution of 0.05", and a depth of 24 or 25 mag.

    "Not only does the GEMS study cover a large area at high resolution; it is also a three-dimensional map. Of the 60,000 or so galaxies that have been identified in the mosaic, distances have been found for 10,000 using another deep survey of the same area carried out with a 2.2-meter telescope at the European La Silla observatory in Chile."

    "Jogee [a GEMS team member] looks forward to learning more about multiple-galaxy interactions, black-hole formation, the host galaxies of active galactic nuclei (of which there are about 80 in the survey), and mergers of spirals to become ellipticals. Of course, the observers work closely with theorists who devise ever-more-detailed computer simulations of the various physical processes that play a role in galactic evolution."

    "This is becoming a very well-studied bit of sky. The GEMS field coincides with the extended Chandra Deep Field, which was imaged in X-rays by the Chandra X-Ray Observatory. The central fifth of the GEMS field is being imaged more deeply by the many-wavelength GOODS Survey. And within the GOODS area we will soon see will the smaller, deeper Hubble Ultra-Deep Field (UDF), the size of a single ACS camera frame. The UDF is currently scheduled for release in March."

  2. jcsd
  3. Jan 13, 2004 #2
    All I have to say about the image that I just saw on that news article is wow. My comments on it are such as:
    1. Great Ideas had to go into this to make it happen.
    2. Thanks should be handed out to all of the scientist and engineers that helped make this happen, and even a more special thanks to the astronauts that risked their lives up in space to create the hubble telescope, and keep it operational for us.
    3. Might they be able to use that Radiation technique that you were talking about in an earlier post to help them with the mapping of these galaxies and such according to the position of the earth?
    -Bob Smith
  4. Jan 13, 2004 #3


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    Glad to hear that you enjoyed this Bob, and welcome to Physics Forums.

    re 3, would you mind pointing to which particular 'earlier post'? I'm afraid I sometimes lose track.
  5. Jan 13, 2004 #4
    Ah, oh, my mistake, i got names confused. I saw Nareid, and Nibles, and i confused you two. Nibles had brought up something in this post that had something to do with the radiation of stars being used to track their positions in the universe.
  6. Jan 13, 2004 #5


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    Hey Nereid, half a degree wide is the size of the full moon
    a pretty nice size patch of sky!

    so ellipticals form by the slow merger of spirals
    and Milky may someday be one (after consuming Andromeda?)

    wish I had a poster of that GEMS picture to put on the study wall.
  7. Jan 13, 2004 #6
    Re: Re: GEMS - a rich trove of information about galaxy evolution

    This has been theorised by astronomers studying the formation of globular clusters. See this review article, for example:

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