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Study Details What Happens When Galaxies Collide

Posted by samzenpus on from the it's-full-of-stars dept.

Aspiring Astronomer writes: According to a recent study, when two galaxies of a similar mass collide, both galaxies will begin producing more stars. However, when one galaxy considerably outweighs the other, the larger galaxy begins producing more stars, whereas the smaller galaxy's star production begins to slow. This may be because the larger galaxy is able to draw gases from the smaller one, resulting in the formation of more stars. The Milky Way may experience a collision of it's own, because the Andromeda Galaxy is moving towards us at speeds upwards of 200,000 miles per hour. No need to worry, though; this collision is a few billion years away.

10 of 52 comments (clear)

  1. Where baby stars come from. by sharkbiter · · Score: 4, Funny

    When a papa galaxy and a mama galaxy love each other very much...

  2. Oh. Darn. by NoNonAlphaCharsHere · · Score: 3, Funny

    I assumed this was a video of Samsung phones being fired at each other.

  3. On behalf of the rest of the world by Swampash · · Score: 3, Funny

    What is a "mile"?

    1. Re:On behalf of the rest of the world by michelcolman · · Score: 2

      OK, so it's just over five kilofeet then? Why don't they just say that?

  4. Andromeda has A TRILLION STARS by yo303 · · Score: 2

    Our galaxy has only a hundred billion. Knowing us we will go to war long before we collide, though.

    PREPARE FOR WAR AGAINST THE ANDROMEDA GALAXY!

    1. Re:Andromeda has A TRILLION STARS by swilly · · Score: 2

      The Milky Way is estimated to have 200 to 400 billion stars. However, just counting stars doesn't tell the whole story. The total mass of Andromeda is estimated at 1.5 x 10^12 solar masses, which is roughly double the 8.5 x 10^11 solar masses estimated for the Milky Way. Still pretty big, but not the 10x you are suggesting.

      Of course, that is our best information at present. Historically, estimates have varied quite a bit. Back in 2006 there were a bunch of news articles stating that the Milky Way had fewer stars but more mass from dark matter. And then Andromeda was determined to be four times more massive. And now it's only twice as massive. I expect this to be significantly revised as we learn more about both galaxies (especially our own: it's harder to learn size, shape, and mass from inside than it is from outside) and as we learn more about dark matter.

  5. Almost there... by Alwin+Henseler · · Score: 3, Insightful

    Just a few words shorter, and even /. users may read the article.

    Btw. since galaxies are mostly empty space, "to collide" doesn't sound right, imho. Two galaxies "mingling" might be a better description. A star from galaxy A here, a star from galaxy B there, a cloud from galaxy A over here, a few 'minor' collisions here & there, etc. Kind of like how 2 clouds of powder would 'collide'. And of course taking place over a long time span.

    1. Re:Almost there... by behrooz0az · · Score: 2

      Didn't you read the GP? no touching

      --
      Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion. -- Spazmania (174582)
    2. Re:Almost there... by michelcolman · · Score: 2

      But once they "collide" (mingle), how can you still say that one galaxy is producing more stars than the other? I mean, doesn't it just become one big mess?

  6. Re:spectrum by michelcolman · · Score: 3, Informative

    Yes, that galaxy is indeed blueshifted. Who told you that "all the stars" are redshifted? When you look at the night sky, you'll see about the same number of blueshifted as redshifted stars, since the vast majority of them are in our own galaxy and we're all just revolving around the center. And the galaxies in our immediate vicinity are kind of clumping together, not expanding. When you look at objects outside our local cluster of galaxies, yes, those do all appear redshifted. The further they are, the more redshifted they appear. And that indeeds indicates that the universe is expanding. But in our local neighbourhood, there's plenty of blueshifted stuff.