Galaxies Floating on a Dark Matter Stream

Darkman, Walkin Dude writes "A team in Switzerland has discovered that most of the small satellite galaxies around the Milky Way's near-twin, Andromeda, are lined up in a single plane that slices through Andromeda's spiral disc. Using images from the Hubble space telescope, soon to be decommissioned, the researchers found that 9 of the 14 of Andromeda's satellites lay on a relatively narrow plane bisecting Andromeda. From the article: 'The team believes the plane could have formed in several ways. In one scenario, the galaxies may have fallen towards Andromeda along an invisible filament of dark matter. Computer simulations show these filaments can form a cosmic web along which galaxies flow.'"

Comments

Sombrero Galaxies and You

[eldavojohn]

These are called Sombrero Galaxies. I believe M 104 is the most famous since it was first noticed on May 11th, 1781.

Does dark matter hold our universe together in a web? Perhaps, though this would mean that there is no such thing as truly empty space as a small amount of dark matter would have to exist. Perhaps what lays beneath the edges of our universe is nothing in the sense of it being devoid of dark matter?

Check this out:

Consider this fact: In the air we breathe, each cubic centimeter contains roughly 5 X 1019 atoms. In contrast, the intergalactic medium has a density of only 10-6 particles per cubic centimeter--each atom inhabits a private box a meter on each side. This would seem to suggest that there is not much matter in the intergalactic medium. But, given the enormous volume between the galaxies, it quickly adds up: The combined atomic mass of intergalactic gas exceeds the combined atomic mass of all the stars and galaxies in the universe--possibly by as much as 50 percent! There is indeed something in empty space

From this article.

While this article only mentions computer simulations, many scientific groups have gone along further researching, convinced that the cosmic web does exist. Some people have based most of their work on dark matter and the cosmic web though I believe it is still speculation and has yet to be accepted by the science community as a whole. I've read some crazy stuff about dark matter, like how it might be the "gravity particle" that is attracted to matter uniformly and causes the gravitational pull between objects. And even crazier books suggesting that the only way we'll ever be able to communicate between parallel existences is by lowering and raising these gravity particles.

Now, the slashdot community seems to be fairly educated and extremely opinionated so how about it--does dark matter exist? If so, since it is very difficult to detect, what are its defining properties?

Eric Lerner

[Bloater]

The team believes the plane could have formed in several ways. In one scenario, the galaxies may have fallen towards Andromeda along an invisible filament of dark matter. Computer simulations show these filaments can form a cosmic web along which galaxies flow.'

Eric Lerner is looking less and less like a crank with every new cosmological experiment, I think this is exactly what his plasma filament theory of the intergalactic medium has been predicting.

a name for it

[heatdeath]

If they eventually find more evidence for these "dark matter streams", and start naming them, I think "the styx" would be a completely awesome name for such a stream.