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Space Science

VLT Smashes Record of Farthest Known Galaxy 39

Posted by Hemos 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."
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VLT Smashes Record of Farthest Known Galaxy More

VLT Smashes Record of Farthest Known Galaxy

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  • I suddenly feel so young!
  • Okay, I know little about this subject. So will it be possible for them to someday see the beginning of the universe?

    • Re:The Beginning (Score:3, Informative)

      by Sidoine ( 647373 )
      No, initially the Universe was not transparent.

    • Re:The Beginning (Score:5, Informative)

      by barakn ( 641218 ) on Monday March 01, 2004 @01:23PM (#8430589)
      We can only 'see' back to when the cosmic background radiation first escaped from the hot plasma of the Big Bang (when it had cooled to about 3000 K). There is some speculation that we might be able to see through this using gravitational waves.
      • Ok, I get the concept that looking at distant galaxies is looking back in time due to how long it took light to get here.

        But how is it that we can keep looking further and further away. Wouldn't there be a point in time beyond which we can't see since the universe just isn't wide enough to have had any light traveling for that long? i.e. if the furthest object is 10 billion light years away, then we wouldn't be able to see any further back then 10 billion years???

        The only way I can see around this is if

        • Re:The Beginning (Score:5, Informative)

          by Doctor Fishboy ( 120462 ) on Tuesday March 02, 2004 @12:02AM (#8436898)
          You're completely right about the point in time beyond which we wouldn't see any more, and you're right about the expansion of the universe being faster than the speed of light. So it means that the whole universe may be many trillions of light years (or even infinite) in size, but the oldest light we can possibly see is that from less than 13 billion light years away (rough age of the universe).

          General Relativity *does* allow separate parcels of space to move apart from each other faster than the speed of light, in that GR is only valid for local inertial reference frames. Space *itself* is doing the expanding, and not the interaction of mass and energy sitting through it, which is what is described by GR. Sorry, I'm not a GR physicist, so I can't give a good explanation for what seem like a cheat in GR, but it is apparently valid.

          Your last line is partly true, in that the universe is thought to have had an era of insanely rapid expansion - one doubling of its effective size every 10**-34 seconds or so - for many tens of thousands of doublings, back when the universe was about 10**-30 seconds old. It's called Inflation theory, and it was created to explain why the effective temperature of seemingly separate parts of the universe is very very similiar. The argument is that the universe we can see (and anything beyond 13 billion light years away) was, at one time, in thermal equilibrium with itself, and then this inflation era blew up the universe faster than the local speed of light in any causal region.

          Erm. Just had a few beers, so this may not help, but go check out "The inflationary Universe" by Alan Guth, who explains it a lot clearer than me at the moment :)

          Cheers,

          Dr Fish
  • 13,230 million light-years away

    So 13.23 billion light years.

  • Links to an easier to read summary (Score:5, Informative)

    by rduke15 ( 721841 ) <rduke15@gm[ ].com ['ail' in gap]> on Monday March 01, 2004 @11:12AM (#8428860)
    Here is an easier to read summary [www.nzz.ch]. More keep appearing on Google news. Try this search [google.com]. It already brings up a link to a space.com article [space.com], and to one in the Los Angeles Times [latimes.com] for those of you who have a subscription (I don't).

  • End of galaxy (Score:2, Interesting)

    by Anonymous Coward
    Has anyone decided what's past the expanding universe?

    I mean what's it expanding into?

    • 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.

      • WMAP [astronomy.com] showed that the universe is flat beyond reasonable doubt.

        I don't understand your point about "true movement". If the distance between two objects changes as a function of time they are said to be moving.

        Simon

    • It's expanding "Into" itself (Score:5, Informative)

      by rpresser ( 610529 ) <rpresser&gmail,com> on Monday March 01, 2004 @02:00PM (#8431117)
      You can think of it (in mathematical terms) as a mapping of R^3 onto itself which expands distances.

      An analogy that may help:

      Take a circular rubber sheet. Draw some dots on it. Pull the sides of the rubber sheet and watch the dots separate.

      Now imagine your rubber sheet started out as an infinite plane: it is no more infinite after stretching than before, yet all distances have increased.

      Now generalize from an infinite plane to an infinite volume, and you should get the idea.

    • Re:End of galaxy (Score:5, Interesting)

      by WasteOfAmmo ( 526018 ) on Monday March 01, 2004 @02:09PM (#8431260) Journal
      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.

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

        Your theory of a donut shaped universe is intriguing. I may have to steal it.
        TZ

  • Only one line detection? (Score:5, Interesting)

    by Doctor Fishboy ( 120462 ) on Monday March 01, 2004 @11:50AM (#8429302)
    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. [unige.ch]

    • Re:Only one line detection? (Score:5, Interesting)

      by elliptical_boy ( 110185 ) on Monday March 01, 2004 @03:35PM (#8432558)
      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

  • It give new meaning to... (Score:5, Funny)

    by SirTreveyan ( 9270 ) on Monday March 01, 2004 @01:13PM (#8430443)

    a long time ago in a galaxy far far away...

    I know...but someone had to do it...

  • Ahem.. (Score:4, Interesting)

    by Transcendent ( 204992 ) on Monday March 01, 2004 @02:05PM (#8431191)
    ...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.
    • correction: ...assuming it's 13.7 billion years old ;)

      That would make it around 0.966c though.
    • Similar to the parent, I wonder that the newly observed galaxy must have been pretty close to the center of the universe when the observed light was emitted, and if I expect we aren't at the edge of the universe here, therefore the universe can be around, lessay, 15-25 billion light years in radius (30-50 in diameter). Can it have grown so much in the 13+ billion years?

      • First, there is no center or edge of the universe. Second, at the time the light we now see was emitted from the galaxy, we were much much closer to the galaxy.

        One way to think about that is to think about the surface of a sphere. Not the sphere itself, but just its surface. There is no boundary, there is no center. There are no privileged locations on the surface of a non-rotating sphere. Of course, this is a 2-d finite example. If the universe is infinite, then "radius of the universe" doesn't hav

    • Err, we don't need to know anything about the speed we have been moving at to get the time.

      It's 13.2 billion ligh years away so the light we are seeing now is 13.2 billion light years old because that's the time it takes for it to travel here.
  • The assumptions about the link between red-shift and age are correct. It has been postulated that other factors, like dark matter or dust, could cause apparent red-shift..

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