Posted on 01/30/2008 12:04:13 PM PST by Freeport
A mushroom-shaped hydrogen cloud rearing 1000 light years above the plane of our galaxy is the aftermath of a massive gas cloud that dive-bombed the Milky Way, new computer simulations suggest. The work explains why the cloud is unlike any other found so far.
The cloud, called GW 123.4-1.5, was discovered in 1999 by Jayanne English of the University of Manitoba in Winnipeg, Canada, and colleagues, who found it in a radio survey of the galactic plane. Two explanations for its familiar shape were offered at the time – that the mushroom is a bubble of gas blown out by exploding stars in the Milky Way, or that it is the remnant of a gas cloud that punched through the galaxy.
Now, 3D computer simulations led by Chang Hyun Baek of Sejong University in Seoul, Korea, bolster the latter possibility.
The simulations show that the cloud's size, shape and velocity can be produced if a hydrogen cloud with 100,000 times the mass of the Sun slams into our spiral-shaped galaxy at 100 kilometres per second and punches through to the other side. The event would have had to occur about 50 million years ago to match the present-day observations.
Head-on crash The study may also explain why no other, similarly shaped clouds have been found so far. The scientists found that mushroom shapes only occur in "head-on" collisions – when the incoming gas cloud's trajectory is no more than 5° away from being perpendicular to the galactic plane. Only a small number of the gas clouds that hit our galaxy would come in at such an angle, making mushroom-shaped clouds a rarity, the scientists say.
(Excerpt) Read more at space.newscientist.com ...
There are two topics in the General/Chat forum that are ideally-suited for this sort of a thread. Please make a note of them.
Ping
Bush’s Fault.
Cool
Uber nuke o_O!
Galactic Warming, there you go!
Sheesh. Even the Universe can’t digest Hormel Chili.
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