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Galaxy from 700 million year old universe

  1. Feb 15, 2008 #1


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    One of the earliest, maybe the earliest galaxies seen so far.
    Redshift 7.6 reported at conference. If confirmed then the light from it has been traveling some 12.9 billion years and was emitted when expansion was only about 700 million years old.
    Put 7.6 into either of these calculators to get distances and recession speeds
    Ned Wright's
    just plug in 7.6 for z, over on the left

    Ned Wright puts in the default values of H=71, and Omega_matter = 0.27 and Lambda = 0.73. they are accepted parameter values, widely used. With Morgan's calculator you have to type in those three parameter values
    Over on the left, put in 0.27 for matter, 0.73 for Lambda, and 71 for Hubble.

    Here is a press release about it, and a blog report from the conference:

    Larry Bradley, Garth Illingworth, Rychard Bouwens are some names to search on, to find out more.
    They had 10X gravitational lensing magnification by a galaxy in the foreground. The James Webb telescope (launch 2013?) will be able to see detail in this young galaxy.

    The recession speed was 3.3c THEN when it emitted the light we are now receiving from it, and its recession speed now is 2.1c
    (you can check this with Morgan's calculator if you wish)
    When it emitted the light it was about 3.4 billion lightyears from us. And today, as we are receiving the light, it is about 29.4 billion lightyears from us.

    the ratio of those two distances should be 1+z = 8.6 because that is the factor by which distances have grown during the time the light has been in transit.
    Last edited: Feb 16, 2008
  2. jcsd
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