Hubble and Spitzer find most distant galaxy

By Phil Plait | February 12, 2008 11:30 am

Hot on the heels of that fabulous Spitzer image comes news that Hubble and Spitzer have teamed up to find what may be the most distant galaxy ever seen. It appears to be at a distance of 12.8 billion light years.


Here’s the image (click to make it more cromulent):

The big image shows the incredible galaxy cluster Abell 1689, a well-studied city of galaxies. The combined gravity of the galaxies in that cluster act as a lens, distorting and magnifying the light of galaxies on the other side, more distant galaxies that might be too faint to be seen on their own. The arcs you see are all more distant galaxies, their light strewn out by the gravity if the intervening cluster (see how they all appear to have the center of the cluster as their own center of curvature?).

Even boosted by this gravitational lens, the light of the distant galaxy named A1689-zD1 is too faint to be detected in the visible, but Hubble’s infrared camera NICMOS got a peek at it. Then the Spitzer Space Telescope was able to see it even more clearly, as can be seen by the three images on the right.

The more distant galaxies we see, the younger they are, because it takes light a long time to cross the Universe. We see this galaxy as it was when the Universe itself was only about a billion years old. Astronomers are not sure how long it took galaxies to form after the Big Bang, but every time we look farther away, we still see galaxies. Mind you, the ones we see have to be fantastically bright, so they may be skewing our view (there may be much dimmer ones, but they are as yet too faint to see). But the point is, we do see galaxies at this fantastic distance.

The distance was determined by looking at the colors of the galaxy. The Universe is expanding, and more distant galaxies recede from us more quickly. This stretches the light from distant objects out, making them redder, a cosmic variation on the more familiar Doppler shift that makes car engines make that WWEWEEEEEOOOOOORRRR sound as they pass. By knowing what kind of light a young galaxy emits, and then comparing it to the amount of light in each image, the amount of redshift can be estimated, and the distance determined. For A1689-zD1, it’s invisible in visible light, detectable at near infrared wavelengths, and stronger yet in the longer infrared colors. This indicates a tremendous redshift, and therefore a great distance.

From my rough calculation, it may be possible to nail down the redshift using STIS, a camera on board Hubble. STIS is currently dead, the victim of an electrical short. However, astronauts will attempt a repair of it in September during the Hubble servicing mission. I wonder if it’s worth trying to observe the galaxy… it’s a marginal observation; it’s possible that even if STIS can detect this faint smudge, it will only be able to give us a lower limit to the distance (in other words, the data will say that the galaxy is at least at a distance of X billion light years, but not tell us what the actual distance is). Still, it might be worth a shot.

By knowing the distance to this galaxy, and examining the way it emits light, we can put yet another data point in our models of the early Universe. We’re still trying to figure out just what the heck the cosmos was doing back then, and every time we see farther back, we nail down a little bit more about this place we live in. Observations like this one from Hubble and Spitzer propel us that much farther in our understanding.

Comments (56)

  1. Cusp

    Haven’t we been around this bush before with results like;

    and their ilk?

    When I see “real” spectroscopic confirmation, I’ll believe it

  2. Thing is, when you have a distance record, it’ll eventually be broken. This isn’t like the news headlines we see over and over again like “Best evidence yet for black holes”; this is a numerical measurement that can be bested.

    In this case, I do agree that the distance isn’t confirmed, but the method used (called photometric redshift) has been tested many times and it appears to work well. Still and all, I’d like to see a spectrum with a big ol’ bump at 10,400 Angstroms indicating the Lyman Alpha line at z=7.5.

  3. zer0

    BA, could you help me wrap my head around the semantics of calling a distant galaxy young vs. old. I always thought the further we looked in the galaxy the “older” things were, because we’re seeing them as they were. But it seems astronomers call them “young” because the Universe was really young when they formed? I guess I’m just missing the trolley on this one.

  4. Duane

    Is there any way to tell how many actual photons struck the detector to create the image? It’s amazing to me that at 12B light years, there were any at all that survived absorption and gravitational lensing to make it to the telescope.

    And speaking of telescopes (please forgive the diversion from the original topic), we know that there are certain animals (hawks, for example) that have extraordinary eyesight. Is there anything we can learn from the animal kingdom that can be put to use in creating more powerful telescopes?


    The distance record is a problem only if you are a narrow-minded dogmatic scientist which puts his misguided faith in the big-bang and Darwin.

    By contrast, these data once again show that the age of the cosmos can’t be any older than 6000 years.
    And, guess what? THE BIBLE TOLD YOU SO, Bad word deleted! [Please, satire is fine and all that, just keep it polite and don't use bad words. -TBA]

  6. Dave72

    Response to Zer0

    Just compare it to looking at a very old photo of grandpa when he was very young

  7. I’d just like to say I love the phrase “city of galaxies.” :)

  8. zer0, we see them as they were when they were young. The light we see left that galaxy nearly 13 billion years ago, when the galaxy was young, and has been traveling all that time to reach us.

    Wanna get even more confused? The Universe has expanded since that light left the galaxy. So actually it’s much farther away “now” than it was “then”. So the distance I mentioned is really only how far the light had to travel, not the actual distance to the galaxy. :-)

  9. Michelle

    …Thanks BA, my head just exploded.

  10. Cusp

    Photometric z work reasonably well when you know your template – but high z claims have come and gone. What’s really needed is a spectrum. You don’t need HST, a nice big light bucket like Keck will do :)


    I apologize profusely for having unknowingly broken the rules of the house.
    Having said that, the fact that you deleted part of what I said, is testament to the fact that you can’t stand the revealed truth, even though He sent his only begotten son to die on the cross for your sins.

  12. Here’s what I don’t get… how can these distance predictions based on redshift be anywhere close to accurate? A small error in the amount of light that hits the detector and being slightly off on the amount of light we “think” the galaxy should produce, would produce wildly different numbers for the distance once calculated…

    Is there an upper limit to the resolution we can discern from observations? There are probably two limits… the physical and the current technological. I’d just like to know at what point can we not gain any more information because what we are looking at is just too far away to produce more than a small collection of photons once it reaches earth.

  13. Flonkbob

    Uh, I worry about ol’ GOD_OF_THE_CAPS a bit.

    Of course I worry about anyone who listens to invisbile sky fairies.

  14. decius

    Mark, apparently the measurements of the redshift are more accurate than the trigonometric calculations used to determine the distance of the stars in our galaxy.

  15. Michelle

    …Any chance that God of the Caps dude is serious? I’d be worried for him too :P

  16. decius

    Michelle, I confess. It was I in a lame attempt at satire.
    I realize now that the line between actual religious lunacy and pretended one is too blurry for it resulting in anything humorous.

  17. ATGreat

    I got into a debate with someone about if the universe is infinite or if it has a finite size based on how far it has expanded since the Big Bang and if the Microwave background marks the “Edge of the Universe”.
    So is the Universe infinite but looks finite or it is finite but looks infinite or is it more confusing then either of those two options?

  18. sean hogge

    What does it take to determine if a galaxy is moving toward or away from us? A difference in the redshift over time?

  19. firemancarl

    What a great photo. I have always like astronomy and I love it when new discoveries are made public. How does anyone not see these pictures or look up in the night sky without a sense of awe?

    I cannot wait to see what other pictures Hubble can produce when it’s all fixed up.


    I saw a show about the super- duper- niffy – spiffy telescope on Paranal. When’s that going to be up and running and what kinda pics can we expect from it?

  20. Chip

    >>>decius asked: “So is the Universe infinite but looks finite or it is finite but looks infinite?”<<<

    Just picture a finite-yet-unbounded 4D manifold that is rapidly expanding yet not into a preexisting space, and has no center. ;)

    Actually, the BA has some entries on this topic, try searching in his “Bitesize Astronomy” and the search feature in the upper right corner above.

  21. decius

    Chip, I never asked such thing. My team of lawyers will be in touch with you.

  22. ATGreat

    Chip, It was I that asked the question about Infinite Universe not decius. :)
    I did check the Bitesized Astronomy part of the site, and found stuff about an expanding universe, but nothing about is the expanding universe infinite or not. There has been a lot of discussion about an expanding universe here and at the BAUT forum, but I haven’t found anything about anybody saying infinity or not infinity or why the question is not a good question. And it seems to be a harder question to ask then I want it to be. :)

  23. Chip

    decius – Oops my bad. :D

    ATGreat – its the BIG topic alright. You might also try over at MadScientists:

    or Ned Wright’s Cosmology Tutorial:

  24. Caleb

    Interesting. I recently submitted a question to “Ask an Astrophysicist” about our being able to peer closer and closer to the beginning of the universe. Here’s the reply I got from Michael Loewenstein and Amy Fredericks (coming from Mike’s email address):

    My Question:
    Given estimates of the age of the universe being 10 – 15 billion years
    old and our beginning to observe galaxies with an estimated age within
    this range (ie: Abell 2218 cluster), do scientists expect to be able
    to view the actual birth of the universe (or at least the first light
    ways emanating from it)? And if so, are there any expectations as to
    when we may be capable of doing this and what ramifications this would
    have on our understanding of the universe?

    Their Answer:
    Thank you for your question. While the age of some of the galaxies in
    the Abell 2218 cluster are indeed very old, we are actually observing
    them as they appear at a relatively recent epoch (about 2 billion
    years ago). Abell 2218 acts as a gravitational lens that allows us to
    see a very distant galaxy behind it that we observe as it appeared
    less than a billion years after the Big Bang.

    Our best bet for probing significantly earlier than this probably lies
    with the James Webb Space Telescope (JWST) — the successor to the
    Hubble Space Telescope — that will hopefully be launched in 2013 (see JWST could observe the very earliest
    luminous objects such as powerful explosions of very massive
    primordial stars (hypernovae), and “mini-quasars”, that formed perhaps
    100 million years or so after the Big Bang — before the first
    galaxies assembled. This will be complemented by radio observations of
    neutral gas by the Square Kilometre Array (,
    to be completed around 2020. These observations will allow us to test
    (and, undoubtedly, lead us to modify) our theories about the formation
    and evolution of structure and the first stars, and the assembly of

    Note that we can never directly see beyond a redshift of about 1000
    (corresponding to about 400,000 years after the Big Bang), since only
    then did the the universe become transparent to radiation.

  25. ATGreat

    Chip, Thanks, this is what I was looking for.

  26. Well, I’m certainly confused by all this talk of infinity, red shifts, and expanding universes. Would anybody rather talk about Britney Spears? That I can handle.

  27. It’s not a Doppler shift, it’s a cosmological redshift, which is a special case of a gravitational redshift…

    Chip: the Universe itself may well be infinite, but the *observable Universe* is finite. (The “observable Universe” is that part of the Universe from which light has had time to reach us since the beginning.)

  28. skeptic23

    In response to a few questions above:

    The galaxy, based on where it is, has been strongly gravitationally lensed. This lensing has increased the total flux we receive from the object probably by a factor of 20′ish (judging from typical magnifications of other strongly lensed galaxies) over what would have been seen if the lens was not there. Because of the strong lensing, we’re also not seeing the galaxy where it really is – the true location is somewhere behind the large galaxies in the center of the cluster.

    Photometric redshifts are performed by taking assumed spectral energy distributions (amount of light per unit wavelength) for galaxies, and redshifting them to find the closest match to your measured colors. This is purely a relative color argument, not an absolute photometry argument, so as long as you get the amount of light wrong in all passbands by the same ratio you’re still ok.

    Tests of photometric redshifts are limited to relatively bright (as deep hst pointings go), nearby (z5 galaxy to appear where that one is located. This only a general argument though, so once can probably create a lensing model for a lower redshift object that would appear at that location, although with significantly less magnification.

    Finally, as to why the light makes it to us – most of the universe is so empty that you only get occasional hydrogen or helium nuclei and electrons. No heavier elements, so no way to make dust, which is what does most of the light absorption in denser environments. Further, the light is redshifting as it travels (due to the universe expanding), and redder light can make it through dust better than bluer light.

    In the end, of course, this is just a press release, and we need to wait for the paper to see how much of this is hyperbole and how much is real.

  29. skeptic23

    Forgot that greater than and less than signs can’t be put into blogs like this, so lost a paragraph and a half.

    The missing paragraphs basically argued that photometric redshifts only have been test to z less than 4 or so, and for much brighter galaxies than this one, so have to be taken with a grain of salt. You could achieve the lack of visible light detection of the galaxy with a large amount of dust internal to a lower redshift galaxy as well.

    The location of the galaxy though does argue in favor of the higher redshift, as in strong lensing a higher redshift galaxy image appears further from the center of the lens than a lower redshift galaxy (in general). That image is located at larger distance from the main cluster than are many of the known lensed galaxies that are at z of 1 to 3 (although there are a few more at even larger radius, which is why I mention it’s only a general argument – specific lens models can put certain galaxies at larger radius).

  30. Hecubas

    In the image, the upper right one labeled Visible Light Hubble, are all those little flecks… stars or more galaxies?

  31. Cusp

    >> It’s not a Doppler shift, it’s a cosmological redshift, which is a special case of a gravitational redshift…

    There is a single redshift, not a bunch of “different” redshifts. There is a simple, single formula for energy in relativity E= -p.U and a “Doppler” shift can be transformed into to a “Cosmological” shift with a change of coordinates in some cases (in others a cosmological becomes a gravitational + doppler – but this is all semantics – there is one redshift)

  32. Greg in Austin

    Lugosion said, “Well, I’m certainly confused by all this talk of infinity, red shifts, and expanding universes. Would anybody rather talk about Britney Spears? That I can handle.”

    Infinity: The amount of money Britney Spears could have made, if she had not gone bonkers
    Red Shifts: Did she shift the color of her hair to red BEFORE or AFTER she shaved it all off?
    Expanding Universe: Britney’s pants.

    Got any more jokes? Something about Britney’s gravitational pull? The black hole into which her career is disappearing into?

    p.s. sorry if this was offensive to Britney fans or astronomers!

  33. Cusp

    [Not a Britney fan, although everyone should cut the poor woman some slack - so no, I'd rather not]

  34. dusty59

    the finite/infinite– edge question is one of my favorite quandries.
    IF there were a telescope way out at Abell 1689, would the universe look the same to them?
    I’ll check out the links suggested above.

  35. gingras

    i feel that i have to point out the cromulent remark since no one else seems to be a dork. thumbs up.

  36. David

    I have a question that may be easier for those of you who have your head more fully wrapped around this than I do. If this object is 13 billion light years away, and at some point 14 billion light years or so ago we were at the same infinitely small point, how did we get so far away from this object? In other words, 13 billion light years of space has opened up between where we are now and where this object was 13 billion light years ago, and it only took 14 billion years for that to happen. Wouldn’t this mean that space is expanding at a rate that is very near the speed of light? If so, then wouldn’t there conceivably already be objects that are far enough away from us that they are moving from us faster than the speed of light and therfore we will never see them? If that is true, wouldn’t that be some sort of paradox?

  37. Cusp

    If you believe the measurements of the cosmological parameters, the universe is infinite in extent. Furthermore, it always has been, even at the big bang. The singularity is not all matter at a point, just that the density diverges as we go backwards to t=0.

    The observable universe (a sphere around us over which light has traveled since the big bang) has zero radius at the big bang. As the universe aged, this sphere got larger.

    Yes, things out there are moving away from us than faster than the speed of light. Yes we can see them (this is a topic which is nicely covered in

    Expanding Confusion: Common Misconceptions of Cosmological Horizons and the Superluminal Expansion of the Universe
    Davis, Tamara M.; Lineweaver, Charles H.
    AA(University of New South Wales, Sydney NSW 2052, Australia;, AB(University of New South Wales, Sydney NSW 2052, Australia;
    Publications of the Astronomical Society of Australia, Volume 21, Issue 1, pp. 97-109. (PASA Homepage)

  38. Cusp

    Sorry – should not have put the word believe in there – what I meant is if the measurements of the cosmological parameters are correct, then this implies that the universe is, and always has been, infinite.

  39. I’m sure many of you are quick to dismiss Britney Spears as some sort of ditzy blonde, but prior to her recent breakdown, she had quite the mind. And if you doubt me, I refer you to the Britney Spears Semiconductor Physics site.

  40. Citation_Needed

    If you are going to make claims, please cite your sources. I have only seen a few people use citations. Uninformed people read your comments and take them as fact.

  41. Scott

    I still want to know what the farthest we could theoretically see would be.

  42. Cusp

    > If you are going to make claims, please cite your sources. I have only seen a few people use citations. Uninformed people read your comments and take them as fact.

    Is that directed at me? I did put a citation in.

  43. Cusp

    As for the statement that the universe is infinite – page 382 of “Gravity: An introduction to Einstein’s General Relativity” by James B. Hartle – the spatial extent of any spatially flat cosmological model (which we are with Om = 0.3 and Lam = 0.7) is infinite.

    As for how far we can see – we can see to the horizon (the sphere around us defined by the distance light has covered in 13.6 Billion years) – we can’t see all the way back to this point, tho, as the CMB is optically thick and presents a surface (known as last scattering) which we get light from. It’s a little like looking into a fog bank.

  44. Cusp

    ps – Davis and Linewaver’s first figure shows the universe in “confomal coordinates” – this clearly shows how far we can currently see – and also how far we will ever see (even though the universe has an infinite future, we will only see a finite part of it)

  45. Flonkbob writes:

    [[Of course I worry about anyone who listens to invisbile [sic] sky fairies.]]

    Do you think calling God a “sky fairy” proves anything other than that you enjoy insulting people who disagree with you?

  46. sean hogge writes:

    [[What does it take to determine if a galaxy is moving toward or away from us? A difference in the redshift over time?]]

    If it has a red shift it is moving away from us, if it has a blue shift it is moving toward us.

  47. Cusp writes:

    [[[Not a Britney fan, although everyone should cut the poor woman some slack - so no, I’d rather not]]]

    Thank you for saying that, Cusp.

  48. Paul

    If the universe did indeed start out as a singularity, was it infinitely small, or infinitely large. For some reason we assume without any frame of reference that it was infinitely small when it may well have been both at once (think about it, if space did not yet exist then neither did size) So what does that make the current universe, finite or infinite? And by the way, despite the previous poor attempts at satire, religious people do wonder at the science behind all of this and marvel at the beauty of the universe. And while I am at it, let me ask this question: If space is expanding, and it certainly seems to be doing just that, then is it not also expanding on the microscopic level. Would that makes Planck’s constant actually a variable, varying by the rate of expansion. Would those of you not laughing too hard take at stab at this.

  49. If the universe is 14b years old, and we see galaxies/stars that are over 12b lightyears away, how did we get here so fast? How did we get here 12b years before the light?
    Imagine how embarrassing it must be for that light (the fastest thing in the universe) to spend 12b years traveling across space and finding out we’ve been waiting for all that time.
    By the way, the accelleration of the expansion of the universe is probably caused by a massive gravitational “pull”eminating from beyond the “bubble” in which the universe is located. the closer we get to it the faster we are drawn toward it. Makes sense to me.

  50. Stosh

    hehe you said “cromulent”

    …I don’t know why we even HAVE a bottle!

    Grouchy O!

    I have asked the same (or very similar) question myself. How can mass (a LOT of it, including us) move at almost 85% of the speed of light? At some point, us and that galaxy were supposedly in the same point in space. We moved away at the speed of mass, it’s light moved away at the speed of light. Isn’t something wrong with this picture?


    P.S. In other words, doesn’t there seem to be a problem with current distance estimates, which tend to “embiggen” the universe? (sorry couldn’t resist) :-)

  51. b@man

    Are you all brain dead? If we are looking at a galaxy 12.8 billion light years away. That fact nullifies the BBT. If the universe is only 13.7 billion years old, the furtherest galaxy we would possibly be able to see would be 7.8 billion LY away. The light from this galaxy started this way shortly after the supposed BB. the Big Band theory is dead. It died the day this pic was taken. Cosmic Background Radiation is a moot point. Do the math.

  52. Actually, b@man (#52) what you have done is show your own ignorance of how this all works. Why don’t *you* do the actual math — or Google up something on how the cosmic expansion works — before jumping to erroneous conclusions. I’ll even help you: search on “NED Wright FAQ”.

  53. Graydon

    Isn’t it the case that the fabric of space, the scale-factor of the universe, is expanding, carrying the galaxies along with it? It’s not the case that galaxies are actually travelling at enormous speeds relative to local space.

  54. Mondoman555

    GOD_OF_THE_CAPS is totally correct. I have met God and he told me so. He did however tell me that the 12.8 BLY is not correct, although he refused to give the correct measurement. I suppose God has to have some secrets


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