Slashdot Mirror

← Back to Stories (view on slashdot.org)

Bigger Galaxy Eats Smaller Neighbor

Posted by michael on from the tastes-like-chicken dept.

Mr.Happy3050 writes "CNN is reporting here that the large galaxy Centarus A absorbed a smaller neighboring galaxy 200-400 million years ago. The absorption created a line of blue stars thousand of light-years across."

3 of 40 comments (clear)

  1. Is it "Eat a Star" month and nobody told me? by greenhide · · Score: 4, Informative

    Look at this other article posted on CNN.com yesterday, about an astronomer (Feng Ma) observing a black hole eating another star.

    It looks like CNN was actually a little late on reporting this actually, here's an article on the 7th about the same event. Actually, it looks like Feng Ma actually observed the "belch" the black hole gave out after consuming the star.

    --
    Karma: Chevy Kavalierma.
  2. Just like what happened to Tadpole and The Mice... by mraymer · · Score: 3, Informative

    Here are some pretty Hubble pictures of galaxies feeding. Both the Tadpole galaxy (UGC 10214) and The Mice (NGC 4676) are the result of merging galactic masses.

    --

    "To confine our attention to terrestrial matters would be to limit the human spirit." -Stephen Hawking

  3. Re:Question by drudd · · Score: 5, Informative

    The simplistic explanation doesn't take gravity into account. Think of it as ants walking around on the surface of a balloon which is being blown up.

    So if the ants stand still, they all get further away from each other (the classic analogy).

    Next level of complexity: the ants are walking around with some random direction and speed. Some will be getting closer to each other, as long as their velocity is greater than the spread of the balloon's surface between them (i.e. distance grows by one inch, but they walked an inch and a half, so the two ants are now half an inch closer than they were initially).

    Now you add in gravity (I don't know how to express this with ants... let's just say they feel some desire to walk towards each other, and that desire is related to their distance). So nearby ants feel some force which causes them to walk towards each other. If they are sufficiently close, this force will cause them to move faster towards each other than the inflation of the balloon is moving them apart (as in the second case).

    This is why the stars in galaxies don't fly apart as the universe expands. The gravitational force at those scales is much greater than the expansion.

    Doug

    --
    Venn ist das nurnstuck git und Slotermeyer? Ya! Beigerhund das oder die Flipperwaldt gersput!