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Oldest Spiral Galaxy in the Universe Discovered

Caption: An artist’s rendering of galaxy BX442 and its companion dwarf galaxy (upper left). Credit: Dunlap Institute for Astronomy & Astrophysics/Joe Bergeron

Ancient starlight traveling for 10.7 billion years has brought a surprise – evidence of a spiral galaxy long before other spiral galaxies are known to have formed.

“As you go back in time to the early universe, galaxies look really strange, clumpy and irregular, not symmetric,” said Alice Shapley, a UCLA associate professor of physics and astronomy, and co-author of a study reported in today’s journal Nature. “The vast majority of old galaxies look like train wrecks. Our first thought was, why is this one so different, and so beautiful?”

Galaxies today come in a variety of unique shapes and sizes. Some, like our Milky Way Galaxy, are rotating disks of stars and gas called spiral galaxies. Other galaxies, called elliptical galaxies, resemble giant orbs of older reddish stars moving in random directions. Then there are a host of smaller irregular shaped galaxies bound together by gravity but lacking in any visible structure. A great, diverse population of these types of irregular galaxies dominated the early Universe, says Shapely.

Light from this incredibly distant spiral galaxy, traveling at nearly six trillion miles per year, took 10.7 billion years to reach Earth; just 3 billion years after the Universe was created in an event called the Big Bang.

According to a press release from UCLA, astronomers used the sharp eyes of the Hubble Space Telescope to spy on 300 very distant galaxies in the early Universe. The scientists originally thought their galaxy, one of the most massive in their survey going by the unglamorous name of BX442, was an illusion, perhaps two galaxies superimposed on each other.

“The fact that this galaxy exists is astounding,” said David Law, lead author of the study and Dunlap Institute postdoctoral fellow at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics. “Current wisdom holds that such ‘grand-design’ spiral galaxies simply didn’t exist at such an early time in the history of the universe.” A ‘grand design’ galaxy has prominent, well-formed spiral arms.

To understand their image further, astronomers used a unique, state-of-the-art instrument called the OSIRIS spectrograph at the W.M. Keck Observatory atop Hawaii’s dormant Mauna Kea volcano. The instrument, built by UCLA professor James Larkin, allowed them to study light from about 3,600 locations in and around BX442. This spectra gave them the clues they needed to show they were indeed looking at a single, rotating spiral galaxy.

While spiral galaxies are abundant throughout the current cosmos, that wasn’t always the case. Spiral galaxies in the early Universe were rare because of frequent interactions. “BX442 looks like a nearby galaxy, but in the early universe, galaxies were colliding together much more frequently,” says Shapely. “Gas was raining in from the intergalactic medium and feeding stars that were being formed at a much more rapid rate than they are today; black holes grew at a much more rapid rate as well. The universe today is boring compared to this early time.”

Shapely and Law think the gravitational tug-of-war between a dwarf galaxy companion and BX442 may be responsible for its futuristic look. The companion appears as just a small blob in their image. Computer simulations conducted by Charlotte Christensen, a postdoctoral student at the University of Arizona and co-author of the paper, lends evidence to this idea. Eventually, BX442 and the smaller galaxy likely will merge.

Shapley said BX442 represents a link between early galaxies that are much more turbulent and the rotating spiral galaxies that we see around us. “Indeed, this galaxy may highlight the importance of merger interactions at any cosmic epoch in creating grand design spiral structure,” she said.

Studying BX442 is likely to help astronomers understand how spiral galaxies like the Milky Way form, she added.

Caption 2: HST/Keck false color composite image of galaxy BX442. Credit: David Law/Dunlap Institute for Astronomy & Astrophysics

About 

John Williams is owner of TerraZoom, a Colorado-based web development shop specializing in web mapping and online image zooms. He also writes the award-winning blog, StarryCritters, an interactive site devoted to looking at images from NASA's Great Observatories and other sources in a different way. A long-time science writer and space enthusiast, he created award-winning Hubble Star Cards. Use coupon code UNIVERSE to Hold the Universe in your hands. Follow John on Twitter @terrazoom.

Comments on this entry are closed.

  • Paul Cook July 18, 2012, 7:08 PM

    Once again scientists are baffled that galaxies so far back in time can look (some of them) as mature galaxies today. They’re baffled because the Big Bang suggests that they can’t look like spiral galaxies or have “old” stars in them, or even have heavy metals in them, as some have been discovered to have. It’s the Wall of the Big Bang: they’ve come up against theory that they dare not contradict. There must be some other, more mundane, reason these galaxies look billions of years older than they do. It can’t be because the Big Bang theory might not be true–or that the universe might be hundreds of billion years old . . . old enough to look as mature as this one.

    • phelanka7 July 18, 2012, 7:54 PM

      I think it has less to do with a grossly incorrect age estimation for the Universe or the validity of the Big Bang and more to do with our lack of understanding galaxy formation.

    • Torbjörn Larsson July 18, 2012, 10:08 PM

      Of course the current inflationary standard cosmology which replaced the old big bang cosmology (but can still be a “Big Bang” theory depending on your definitions) can still be wrong.

      It is highly unlikely though, because the contenders have all fallen.

      And no, even if you take out the standard cosmology out of a Hubble expansion universe it doesn’t make it “hundreds of billion years old”. Instead you get problems with inconsistencies, stars older than the universe IIRC. But nothing like the rather interesting insights into star and galaxy formation these observations are.

      • Charles L Nelson July 21, 2012, 4:05 PM

        An astronomer proposes a causation for galaxy formation. A ‘younger’ galaxy is found…”cannot happen”…because the earlier ‘explanation’ is in the literature. Sounds Biblical to me…limited knowledge used to explain ‘everything’.

    • magnus.nyborg July 18, 2012, 10:47 PM

      We know the universe exists, and we know it has existed for some time. Now scientists are investigating, and trying to make sense of what are observed with theories. In this process there will be some dead ends, some revolutions, and alot of rejection of theories that dont match observations.
      But this process beats the unsupported statement “God dunnit” any day.

  • Gordon Blacklaw July 18, 2012, 7:33 PM

    The big bang is a theory, the universe is expanding therfore it must have exploded from a single point. I don’t know how many pages full of incomprehensible formulae it takes to create billions of galaxys from nothing but somthing tells me it’s alot.

    • Torbjörn Larsson July 18, 2012, 10:29 PM

      Creationists should comment on science blogs, is is hilarious.

      – Yes, precisely as gravitation is a theory cosmology is. Do you want to test the facts of gravitaion theory by walking out of the 10th floor of a sky skraper? A well tested theory without contenders is a sort of superfact – not only does it comprise the observational facts it is based on but it predicts and tests new facts – it is a set of many facts meshed together.

      – _Every volume_ in the universe expands, or the cosmic background radiation wouldn’t be isotropic. Therefore there is no center “single point” any more than a raising bread of raisins have the raisins expand out of a single point.

      In an inflation cosmology it is an open question whether universes derives from a single Planck scale singularity or several.

      – You can explain a “Coleman-Luca instanton” without reference to any equations at all. It is a quantum fluctuation that makes a universe in roughly the same way that fluctuations can make particles or particle assemblies.

      But if you like equations, this 4 page paper with ~ 20 equations walk you through how a dynamical system analysis shows how universes are zero energy. This means that they can tunnel out of older universes by an “instanton”.

      More importantly for a creationist it shows how we know agencies can’t make universes, it is thermodynamically forbidden that a third party act on a zero energy system. “It seems inconceivable that the cosmos could emerge from any physical system that has nonvanishing total energy. This would require an exchange of energy between the universe and a third system, making a cosmological spacetime an open system from the thermodynamical point of view.”

      – Universes appear spontaneously out of known physical laws. (E.g: Hawking, Krauss.) Theist gods are now known to be neither necessary nor very likely to create universes.

      In the same manner deist gods are neither necessary nor very likely to create physical laws.

      Physical laws appear spontaneously out of known physical theories such as anthropic selection on eternal inflation multiverses or post-selection of universes. (E.g: Susskind, Hawking.)

      I suspect that eventually deism, as theist creationism already has, will fall as an intellectually acceptable alternative.

      • lcrowell July 19, 2012, 12:46 PM

        There is a deeper matter involved as well. General relativity does not give an explicit formalism for the conservation of energy. A conservation law occurs when there is a symmetry that computes a constant of the motion. In the case of general relativity this is a Killing vector K = (K_t, K_i) that acts on a momentum vector P = (E, p) so that K•P = constant. For instance a spacetime with a rotational symmetry has Killing vectors K_i with

        [K_i, K_j] = ?_{ijk}K_k

        This conserves momentum and angular momentum in three spatial directions. For the conservation of energy there is a timelike Killing vector that acts on the energy so that K_tE = constant.

        General spacetimes do not have such Killing vectors. One clue to the lack of such a Killing vector is when the metric components depend on a coordinate direction. Cosmologies such as the de Sitter spacetime have time dependency, which precludes a globally defined Killing vector which conserves energy. The de Sitter spacetime is a case in point for it has a constant vacuum energy density ?. A spatial volume element V increases in size with the expansion of the universe. Consequently the energy in that evolving volume increases.

        In the case of how a cosmology emerges from the vacuum, quantum fluctuations are probably the “seed” for their generation. The dynamics of spacetime can then increase this energy with time. In fact it is probably fair to say that a cosmology is a case where a quantum fluctuation of energy ?E?t = ? (or ?E = ?/?t) is “frozen into place. Another way to see this is that the time t here is not an invariant, but is a coordinate time that is freely chosen by a choice of coordinates or frame. So quantum fluctuations can only be defined locally, as are other quantum results like the Born rule. The question of energy and the role of quantum fluctuations is very difficult to understand. In fact it is an aspect of quantum gravity studies.

        We spend years pounding into the heads of students that energy is conserved. It is then strange to realize that on a deeper level this is only a local law. The universe is far stranger than most of us know or want to admit.
        LC

    • lcrowell July 18, 2012, 11:48 PM

      This is something I wrote a few months ago on the topic of the big bang. This is fairly simple and only based on Newton’s laws. So let us start with the basics.

      Let the distance to some galaxy far away be x. I find that this distance x is changing, so I assign a scale factor a. So the time evolution of a distance x is given by

      x = x(t) = a(t)x(0)

      In this way this motion of any distant galaxy can be compared to this scale factor which expands (or contracts if that were to be the case) with the dynamics of the universe.

      Now consider the next ingredient. The energy E of a particle of mass m moving in a central gravity field by some mass M at a distance r is

      E = (1/2)mv^2 – GMm/r

      The total energy E is constant, and largely can be ignored. In particular if the universe expands so there is no recollapse we can set it to zero. We concentrate on the velocity

      v = dx/dt = x(0)(da/dt) = x(0)a’, prime means time derivative,

      so that (1/2)mv^2 = (1/2)(a’)^2(x(0))^2. Now concentrate on the gravity part. We set r = x, the distance to other galaxies, and we assign an average density so that the mass M is a sum of all these galactic masses M = ?Vol. The volume out to some radial distance x is then Vol = (4?/3)x^3 = (4?/3)a^3(x(0))^3. We put all of this together and we get the equation

      (a’/a)^2 = 8?G?/3.

      This equation is close to what one gets with general relativity, where here we have just used Newtonian mechanics and gravity. There is with general relativity an additional –k/a^2 factor related to the constant energy E, which for a spatially flat universe has k = 0.

      How the Hubble constant is H = (a’/a), which is a constant in space, but not necessarily in time. The Einstein cosmological constant is ? = 8?G? for some constant vacuum energy density ?, and so the Hubble parameter is then

      H^2 = (a’/a)^2 = ?/3

      For some other mass-energy density, such as matter or radiation, the density is dependent on the scale factor a.

      For those familiar with differential equations the solution to a’ = sqrt{?/3}a is an exponential function. This is the expansion driven universe we do observe. For a small scale factor this exponential is approximately linear which gives the Hubble relation found in the 1920s v = Hd. So for a galaxy as a distance d the Hubble parameter multiplied by that distance gives the velocity. The Hubble parameter is approximately H = 72km/sec/Mpc. For the distance to some galaxy d in mega parsecs (Mpc) one gets the outwards velocity of that galaxy.
      LC

    • delphinus100 July 19, 2012, 12:47 AM

      “The big bang is a theory,”

      And you are using ‘theory’ the way scientists use the word ‘hypothesis.’ ‘Theories’ are constructed on the results of testing hypotheses with experiment and/or observation.

      Look up the word ‘theory’ in any good dictionary. Seriously. Go and look. Plenty of dictionaries on-line. You will see several definitions. Yours is the layman’s use of the word. In science it’s a different one, and it’ll be there. Until you understand that, you will be talking past anyone versed in science…

      And yes, it is simply logical to assume that if, on a large scale the Universe is expanding (if you don’t believe in the Doppler shifts that tell us that, you must not believe in police radar, either…), then at some finite time in the past, everything was all in one…place. It’s the specifics at the very beginning that are still uncertain.

      And if you don’t comprehend the math under those extreme conditions (I admit I don’t), that’s hardly anyone else’s fault….

  • TexasStargazer July 19, 2012, 3:52 AM

    Maybe the universe is highly curved and Hubble is seeing all the way around the universe and viewing a galaxy in our current space-time. It does kind of resemble some familiar galaxies such as M-51.

    • TheDirtBoy July 19, 2012, 5:34 AM

      Scientists have been looking for that curve for years now and have not found it yet. Besides, after 10.7 billion years, that galaxy most likely doesn’t look like that any more. Just like comparing your photo at 6 months old and your current photo, little if any resemblance.

  • tenstripe July 19, 2012, 4:02 AM

    So it took 10.7 billion years for the light from this galaxy to reach our eyes. 10.7 billion years ago means it has been also producing new light for another 10.7 billion years. Does that mean the observable universe is at least 21.4 billion years old or am I just having a brain fart.

    • IVAN3MAN_AT_LARGE July 19, 2012, 11:27 AM

      Does that mean the observable universe is at least 21.4 billion years old or am I just having a brain fart.

      Your latter, not the former, assumption is correct. See: Observable Universe.

    • squidgeny July 19, 2012, 12:36 PM

      Yeah definitely a brainfart, but we all have them :) (especially where the age of the universe is concerned)

      The light has taken 10.7 billion years to get here, which means we’re seeing it at age 3 billion years. Good chance it’s still there, 7.7 billion years later (i.e. now), still producing light. But we won’t see that light until T = 24.4Gy
      (age of universe + 10.7… ignoring expansion and such)

      • lcrowell July 19, 2012, 10:21 PM

        The galaxy is by the Hubble relation v = Hd is moving at

        v = (74km/sec/Mpc)(10.7×10^9ly/3.26ly/pc) = 2.43×10^5km/sec

        which is close to the speed of light. In 3 billion years it will be about 2.4 billion light years away. In fact it will be moving away faster and will have moved somewhat further. Light emitted by this galaxy in 3 billion years will travel a distance of about 13 billion light years.

        LC

  • HeadAroundU July 19, 2012, 4:27 AM

    I think I saw similar ones at Galaxy Zoo. There must be some thread about old spirals over there…

  • Gopal Anantharaman July 19, 2012, 7:55 PM

    This is the thought that I always had. What if the light from the galaxy is really from Milky way itself! We are looking at our own Galaxy’s light which is in some waywent all around the universe which is then spherical and reached us.We realized that earth is round now it is time to realize that the observable universe is also a closed container and not flat.

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