Six billion years ago, two galaxies collided, launching a stream of gas hundreds of thousands of light years away.
One of the most perplexing questions in astronomy is why the most massive galaxies have died.
If you smash two galaxies together, you can actually rip gas out of the galaxy itself."
Most large galaxies have long since ceased producing new stars.
Cold gas that coalesces to form stars can escape galaxies in a variety of ways, including being blown away by black holes.
that galaxies simply cease to exist once all of the raw materials for star formation have been depleted
The Sloan Digital Sky Survey, which catalogued millions of galaxies using a telescope, was used by the research team.