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Cannibal Galaxy the Biggest In the Near Universe

Posted by Soulskill on from the om-nom-nom dept.

The Bad Astronomer writes "Astronomers have found the most massive galaxy in the near universe: an obese, bloated monster that may tip the cosmic scales at 13 trillion times the mass of the Sun, 20 times the mass of the entire Milky Way. The galaxy, called ESO 146-IG 005, sits at the center of a dense cluster of other (but much more lightweight) galaxies, and grew to its present size by eating the galaxies around it. In fact, the so-far undigested cores of at least five other galaxies are still easily seen in the cannibal's nucleus. Astronomers are having difficulty pinning down the galaxy's exact mass, but it's clearly the biggest bruiser within 1.5 billion light years of home."

6 of 118 comments (clear)

  1. Black Galaxy? by Monkeedude1212 · · Score: 3, Interesting

    If a Black Hole is a super dense star, is it possible to have a galaxy of black holes? Or one giant one with an event Horizon as big as a galaxy?

    1. Re:Black Galaxy? by MozeeToby · · Score: 3, Interesting

      By my calculations, a black hole with a radius of 100000 light years would require a mass of approximately 3 * 10^17 solar masses or about 5 orders of magnitude more mass than is present even in this monster galaxy. And of course, all that mass would have to be present within the 100000 light years, this galaxy is much more spread out than that. So no, it's pretty unlikely to have a galaxy sized black hole (and that's even assuming that I did my math right).

    2. Re:Black Galaxy? by mog007 · · Score: 3, Interesting

      In approximately 10^40 years, every galaxy will be nothing but black holes. By then, all stars will either have become white dwarfs or black holes, and the white dwarfs will have even cooled off to become black dwarfs. I suppose there would be some neutron stars for large stars that couldn't reach the mass limit that turns them into black holes.

      But a galaxy of nothing but black holes? Nah. It would require nothing but very massive stars, and these stars are very rare, compared to the number of stars in the universe.

      --
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  2. Milky Way not much "worse"/"better" by sznupi · · Score: 4, Interesting

    ("worse"/"better" - is an act of eating galaxies ammoral? ;) )

    Our galaxy is a cannibal, too...
    http://en.wikipedia.org/wiki/Virgo_Stellar_Stream
    http://en.wikipedia.org/wiki/Monoceros_Ring
    http://en.wikipedia.org/wiki/List_of_nearest_galaxies
    (and those links are just a starting point; BTW, BOINC project Milkyway@home models this)

    --
    One that hath name thou can not otter
  3. Re:Am I the only one by negRo_slim · · Score: 2, Interesting

    who's first reaction was to wonder what it might be like to live there, in the cannibal galaxy's nucleus?

    I thought the very same thing when I was watching Into The Universe With Stephen Hawking, I think the episode was entitled A Brief History Of Everything and at one point they play a computer simulation of galaxies merging and eventually they throw a lot of galaxies together before that piece ends.

    Might be worth looking up as it was incredibly beautiful.

    --
    On the Oregon Cost born and raised, On the beach is where I spent most of my days
  4. Expanding? Runaway? Collapsing? by mindbrane · · Score: 2, Interesting

    Much like the initial debate over the existence of black holes there seems to be lots of wiggle room when it comes to declaring whether the Universe is in a runaway state, whether it's just expanding, or, whether it will collapse. This Standford Uni link gives a quick overview and suggests in ~15bn years it'll collapse to the size of a proton. The Yale Astrophysics Course, IIRC, is strongly steeped in black hole theory and so speaks to the same issues.

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