back to article Does my mass look big in this? Roly-poly galaxy El Gordo more porky than first feared

The latest data from the Hubble space telescope has shown that the furthest fattest galaxy yet spotted is 43 per cent more massive than first thought and was formed by two huge galaxies colliding. The El Gordo galaxy Galaxy with a weight problem, for astronomers at least Galactic cluster ACT-CL J0102-4915 – nicknamed El …


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  1. Martin Budden
    Thumb Up

    However big you think space is... it's bigger than that.

    1. Neoc

      It's big. Really big. You just won't believe how hugely, mindbogglingly big it is. I mean you may think it's a long way down to the Chemist, but that's just peanuts to Space.

      1. Z-Eden

        Downvote? For a Hitch Hikers quote? Some people are born critics...

  2. attoman

    What about the Dark Matter surround?

    We need to see the Dark Matter restructuring (or not) as the collision completes.

    1. Scroticus Canis Silver badge

      We need to see the Dark Matter restructuring (or not) as the collision completes.

      Well that should only take a few more billion years, so keep an eye on it and let me know what happens. Bated breath and all that....

  3. frank ly Silver badge

    re. "three quadrillion times the mass of our sun"

    It would be more useful and a better comparison to know how much bigger it was than our own _galaxy_. Can anybody offer a figure?

    1. Michael H.F. Wilkinson Silver badge

      Re: re. "three quadrillion times the mass of our sun"

      Our galaxy is between 1.0 and 1.5 trillion solar masses, so El Gordo is more than 2,000 times heavier

      Needs a high fibre diet and more exercise

      1. Bunbury

        Re: re. "three quadrillion times the mass of our sun"

        Is there a theory that would explain why such a discrepancy in mass? Hmm. wonder what the distribution curve of galaxy masses looks like anmd what that says about whether there are different processes in play.

  4. Mike Bell

    Big Bang

    It's generally believed that the whole show started off with a big bang, and stuff flew apart from day 1.

    Or, if you want to look at it another way, it's just space that's getting bigger each second.

    Or, if you want to look at it another way, the whole notion of size might be a non-starter because there are no measuring sticks outside the universe, and words such as big and small mean diddly squat in an absolute sense.

    But whichever way I look at it, I can't easily reconcile this image in my mind with the notion of massive galaxies bumping into each other. When a bomb goes off, I'd expect all the bits to fly off away from each other, not go bumping into each other.

    What am I missing? I guess there has to be a simple explanation somewhere.

    1. Bunbury

      Re: Big Bang

      I don't know if the analogy holds but when a bomb goes off you don't expect the materieal to fly apart as individual atoms or molecules. What happens is the casing splits at the weakest points and the forces keeping the rest together as chunks of shrapnel is greater than the force attempting to tear it apart.

      So perhaps the forces keeping areas of the universe together ish were greater than the forces trying to move them apart.

      1. Swarthy Silver badge

        Re: Big Bang (@ Bunbury)

        You are close. Imagine a bomb with the casing coated in bomblets, so the Big Bomb goes off launching/scattering the bomblets, these then go off sending their casings all over, some of those casings may collide.

        Or Fireworks: We've all seen the ones that fan out, and then have secondary shells which them throw sparks in all directions; sometimes, those paths cross. In a firecracker as big as the universe, it is guaranteed that some embers will hit each other.

        1. Mike Bell

          Re: Big Bang (@ Bunbury)

          That's an interesting analogy (bombs within bombs) but it doesn't sound much like a big bang. It sounds like a big bang followed by lots of other little bangs at the periphery...

          1. The_Idiot

            Re: Big Bang (@ Bunbury)


            "...a big bang followed by lots of other little bangs at the periphery"

            i have a horrible suspicion there's a Paris Hilton pseudo-joke-reference lurking somewhere here, but i can't quite put my, um, finger on it. Or anything else... (blush).

            Yes. I know. Coat, please!

    2. Scroticus Canis Silver badge

      Re: Big Bang - What am I missing?

      Er, gravity? The matter flying apart has mass and it is not all spread out completely uniformly. Everything with mass attracts other mass (gravity), eventually the gravitic attraction overcomes the kinetics of flying apart.

      The denser more massive bits more so than the diffuse less massive bits. The dense bits collapsed to form galaxies. The galaxies then attract other galaxies nearby to form clusters, clusters attract other clusters to form super clusters.

      So the galaxies in clusters are not flying away from each other but are slowly falling towards each other in various orbital trajectories. Some collide and merge in the process but all within the cluster will eventually merge into one super galaxy.

      Leaves a lot of empty space between the super clusters which is where the expansion of space-time is still happening. Clear as mud?

    3. mraak

      Re: Big Bang

      It wasn't an explosion, it is an expansion or inflation (think of it as a balloon rather than a bomb, a word "bang" causes confusion). The rapid expansion had the side effects of forming atoms, then particles, etc.. which resulted later in planets, stars, galaxies, dust, meteors, etc.. Universe in general is still expanding. But in our tiny small fraction, which we call "observable universe" with only trillions of galaxies, the local rules apply, not the global rules of expansion.

      Within these local rules, gravity plays much more important role than expansion. Due to gravity,things in space circle around other things in space, which then occasionally cause interference in their paths and galaxies collide. We will collide with Andromeda at some point, but don't fear. Galactic collisions are very slow and the space between objects is so huge, we won't notice anything.

      There are also some mega events happening, like supernova explosions - formations of neutron stars and black holes, that alter the gravitational patterns of the objects, hence sometimes bringing them closer together.

  5. Ian Tunnacliffe


    Serious point here amongst the smart arse ones. If you are going to report on stories like this involving very big numbers do you think you could use exponential notation? We've probably all got our minds around the idea that a billion is more usually 10^9 rather than 10^12, but trillions and quadrillions? Much better to avoid ambiguity I would have thought.

    1. Sorry that handle is already taken. Silver badge

      Re: Notation

      Is there really still ambiguity regarding the scale?

      Asked as an ignorant Antipodean. I grew up with short scale and Wikipedia claims that the entire English-speaking world also uses short scale.

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