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VLT Smashes Record of Farthest Known Galaxy

Posted by Hemos on from the smashing-the-records dept.

rduke15 writes "From this press release of the European Southern Observatory : 'Named Abell 1835 IR1916, the newly discovered galaxy [...] is located about 13,230 million light-years away. It is therefore seen at a time when the Universe was merely 470 million years young[...].' More details and pictures here."

6 of 39 comments (clear)

  1. Only one line detection? by Doctor+Fishboy · · Score: 4, Interesting
    They're basing it on a single emission line detection - that the identified emission line is highly redshifted Lyman alpha. Normally, you'd like at least one or two other emission lines to pin down the redshift uniquely. I can see that they're also arguing that its blackbody color leads to a photometic redshift from z of 9 to 11, but those error bars look mighty big to me, and they're relying on the non-detections short of 1 micron. Any quasar savvy astronomers care to comment? I know you're out there in /. land...


    Even if it doesn't turn out to be a z~10 quasar, this is an excellent piece of detective work. Big kudos to the authors on this.


    Dr Fish


    The detailed detection images from one of the authors.

    1. Re:Only one line detection? by elliptical_boy · · Score: 5, Interesting

      I agree that only one line is suspicious. But the spectral energy distribution --- its optical and infrared colors --- argue pretty convincingly for its idenitification as a high-redshift galaxy (at least for me, as someone who's worked in this subject).

      Moreover, the authors argue in the paper that the object sits on the appropriate gravitational-lensing caustic for a redshift 9-10 object. I.e., if the galaxy in question---Abell 1835 IR1916 --- sits on at the right place relative to the foreground galaxy cluster (Abell 1835), the General Theory of Relativity says that the mass of the cluster should magnify the galaxy by 25 to 100x in brightness (one of the authors, J.-P. Kneib, is a world expert on gravitational lensing).

      Lastly, if the galaxy was at, say, z=2.7, and thus much closer---but consistent with the colors if the galaxy was full of dust---the line would have to be the forbidden doublet of singly-ionized oxygen at 372.62 and 372.89 nm. But this doublet would have been easily resolved by the high resolution of ISAAC, the infrared spectrograph on the VLT used by the authors, but not seen.

      BTW, probably not a quasar --- the IR (restframe UV) colors are too blue compared to the Sloan z=6 clusters.

      The thing that bothers me, though, is the the shape of the Ly-alpha line --- it's asymmetric in the wrong way (too sharp on the red side, too gaussian on the blue side) compared to the z=3 galaxies.

      Still need a lot more data, though --- both deeper NIR spectra to look for the continuum and mid-IR images (perhaps from the VLT, or Spitzer Space Telescope, or eventually the James Webb Space Telescope) to confirm the restframe optical colors.

      Cheers,
      Scott

  2. Re:thousand million? by boarder · · Score: 4, Interesting

    Well, I'm not sure how true that is today...

    Milliard USED to be the Euro term for the U.S. billion, but most nations have switched to the U.S. term for 1,000,000,000. Milliard and the old Euro def of billion are archaic usages, and billion is generally used in the U.S. sense. Check Wikipedia for Milliard and also Wiki for Billion. A google-fight between billion and milliard results in 12,800,000 hits for billion and 235,000 for milliard. Billion wins.

    Of course, I'm American, so I don't know how often the general public in Europe uses those terms and with what meanings; but officially in the government the terms have changed.

    --
    IANAL, but I play one on /.
  3. The universe is infinite by Sidoine · · Score: 3, Interesting

    Or at least it loops if the universe is not "flat", which does not change anything. Anyway, this expansion does not mean that there is a true movement, like in an explosion. The distance between things change, that's all.

  4. Ahem.. by Transcendent · · Score: 3, Interesting

    ...is located about 13,230 million light-years away. It is therefore seen at a time when the Universe was merely 470 million years young

    Assuming that the universe is 13.5 billion years old and that we've been moving away from that galaxy near the speed of light (around 0.965c if my math is correct).

    I would think that finding such a thing would tend to make people think the universe is older.

  5. Re:End of galaxy by WasteOfAmmo · · Score: 4, Interesting
    In fact there is nothing (literally) beyond the expanding universe. It is space itself that is expanding, therefore beyond the universe space, time, etc. does not exist and therefore there is truely nothing.

    It is a hard idea to grasp along with such questions as what is the shape of the universe.

    One of the other replies had it correct.. it is not that the galaxies are moving away from each other, it is that space itself is expanding and therefore the distance between all galaxies is increasing. It was the observation that all other galaxies are retreating from us the lead to the theory that we were at the centre of the universe. Of couse it did not take long to prove this wrong.

    Merlin.