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Galactic Pancake Mystery Solved
mOoZik writes "According to the BBC, Astronomers have figured out why a series of small galaxies surrounding the Milky Way are distributed around it in the shape of a pancake. Theorists believed that the eleven dwarf galaxy companions should have a diffuse, spherical arrangement, but a University of Durham team used a supercomputer to show how the galaxies could take the pancake form without challenging cosmological theory."
The evil Egglons attack, wiping out most of breakfast.
Aha, now all that remains is to find a galaxy shaped like a bottle of maple syrup!
Send email from the afterlife! Write your e-will at Dead Man's Switch.
... and more credit ... (and to enhance discussion :) ...
Full article
The Distribution of Satellite Galaxies: The Great Pancake
Noam I Libeskind, Carlos S Frenk, Shaun Cole, John C Helly, Adrian Jenkins, Julio F Navarro and Chris Power
ABSTRACT
The 11 known satellite galaxies within 250 kpc of the Milky Way lie close to a great circle on the sky. We use high resolution N-body simulations of galactic dark matter halos to test if this remarkable property can be understood within the context of the cold dark matter cosmology. We construct halo merger trees from the simulations and use a semianalytic model to follow the formation of satellite galaxies. We find that in all 6 of our simulations, the 11 brightest satellites are indeed distributed along thin, disk-like structures analogous to that traced by the Milky Way's satellites. This is in sharp contrast to the overall distributions of dark matter in the halo and of subhalos within it which, although triaxial, are not highly aspherical. We find that the spatial distribution of satellites is significantly different from that of the most massive subhalos but is similar to that of the subset of subhalos that had the most massive progenitors at earlier times. The elongated disk-like structure delineated by the satellites has its long axis aligned with the major axis of the dark matter halo. We interpret our results as reflecting the preferential infall of satellites along the spines of a few filaments of the cosmic web.
CC.
TaijiQuan (Huang, 5 loosenings)
It's bunnies all the way down?
ClutterMe.com - easiest site creation on the Net. Just click and type.
Our local cluster is a franchise of IHOP (intergalactic house of pancakes).
... researchers are still working on the mystery of the cosmic sausage and eggs, as well as new puzzling information that seems to indicate the presence of a Great White Handkerchief... or maybe it's a napkin?
Dark Syrup explains galactic pancake mystery.
"Look, I don't want any toast, and he doesn't want any toast. In fact, no one around here wants any toast. Not now, not ever. No toast!"
"How 'bout a muffin?"
"Or muffins! Or muffins! We don't like muffins around here! We want no muffins, no toast, noteacakes, no buns, baps, baguettes or bagels, no croissants, no crumpets, no pancakes, no potato cakes and no hot-cross buns and definitely no smegging flapjacks!"
"Aah, so you're a waffle man!"
This sounds a little like planetary formation. What if these 'halos' were really rings, due to some sort of spin in the original setup? Do they have to be a 3-dimensional halo? I am not an astronomer, but it sounds reasonable to me - could someone please explain this?
Quoth the server, "404."
How much of this kind of research does NASA actually do? It seems that they largely put the satellites in place and maintain them, and universities handle the data analysis.
You can never go home again... but I guess you can shop there.
University of Durham http://en.wikipedia.org/wiki/Durham/
Just 'cause it's not in the US...
...on this pancake, Smucker's already has a patent on it.
...there *are* certain galaxies that look like oranges. http://www.eso.org/outreach/press-rel/pr-2003/imag es/Phot32/phot-32a-03-normal.jpg
I don't get it.
without challenging cosmological theory
Isn't it supposed to be about challenging current theories?
I've got a slightly more than average knowledge base on cosmology (though maybe not more than your average slashdotter). I've read a few books, but one thing I've never cleared up: Why do galaxies form in flat spirals and pancaks, and not in gravitationally stable spheres? Is there a simple reason I'm missing?
-dave
http://millionnumbers.com/ - own the number of your dreams
NASA is about rockets. This isn't the sort of stuff they do really do. They help supply data to astronomers/cosmologists/physicists who apply to them, and who, largely, are affiliated with universities and are not "kids."
Dr. Feynman at CalTech and Dr. Sagan at Cornell, for instance, who were both rather famously at odds with NASA more often than not.
"Citizens" have always handled the bulk of astronomical research.
Because more often than not NASA is the necessary enemy of astronomers. It is a government agency, run for the government's purposes, complete with a government beauracracy, and only provisionally interested in theoretical science at all.
But they own Hubble.
I might also point out that these "kids" weren't even in America. England has a university or two worth a damn that might object to being catagorized as "random", and four or five smart people in them. Germany, China, Australia, and hell (as it were), even the Vatican have quite capable cosmologists of their own.
NASA isn't the center of the universe.
KFG
NASA doesn't really specialize in science. It specializes in complex engineering feats where outside scientists run the experiments. When the Mars Exploration Rovers landed on Mars, the project was run by JPL engineers, but the science data was evaluated by scientists at various institutions (initially the ones who helped design the science payloads).
NASA gets credit for many scientific discoveries due to the fact that they wouldn't be made without the NASA hardware. But NASA does not employ the scientists who make the discoveries (except in a few odd projects like asteroid impact research).
when's the galaxy due to flip over?
Well, maybe *you've* never heard of the University of Durham, but it's one of the foremost universities in the UK, and the Physics group there is extremely well-respected.
This isn't "some kids doing a group project", this is proper academic research; you may have heard of that...
It's official. Most of you are morons.
Yes, but is it perpendicular?
(ducks)
Theorists believed that the eleven dwarf galaxy companions should have a diffuse, spherical arrangement
Sounds like someone's been watching the Lord of the Rings box set a wee bit much.
Please stop stalking me, bro.
The most irritating part of being an astronomer must be constantly defending the allocation of millions of dollars of public funds on whatever it is that they do.
A major new theory in regards to the shape and spacing of galaxies; what difference does it make to anyone?
Any bible-thumping corrupt two-bit schmuck of a politician can come up with a reason why the millions of dollars spent on astronomical research would better be directed towards one of his campaign contributers. And there are lots of those politicians nowdays.
So how actually do the astronomers keep all this money flowing their way? I would suspect that astronomy is 80% math and computer programming now instead of primarily star-gazing.
In the past, it wasn't this hard to justify the astronomers. Gods ruled the stars; kings ruled the people by the grace of the gods; astronomers interpreted the movement of the stars to convince the people that the gods still favored the king, and the king saw to it that the astronomers got plenty of money.
Astronomical research was important in navigation and agriculture. When to plant and which direction to steer when out-of-sight of land was critically important. But real extraterrestial knowledge came slowly. It was only four hundred years ago that Westerners realized that the Earth moved around the sun.
Today the most interesting about astronomy isn't theories about objects billions of miles away, it's how astronomers justify spending millions of dollars looking at objects billions of miles away.
You are absolutely kidding right? I've studied at Durham, UK (Carlos Frenk was my Astro lecturer), QM, London, and Stanford, US, and they all have their fair share of smart people. Calling Frenk, or indeed any of these guys "kids" is way out of line. Than again, I could just chalk it up as yet another example of American insularity. (Go ahead, mod me flamebait, I just don't take kindly to the "kids" vs. "pro" and "university of whatever" thing - it's rude and naive).
Dan