Again, Brent, I'm kicking myself for getting away from space-based SF
writing... thanks for the post. Fascinating to contemplate.
On Fri, Jul 2, 2010 at 11:19 PM, brent wodehouse <
brent_wodeho...@thefence.us> wrote:
>
>
>
> http://www.space.com/scienceastronomy/milky-way-ancient-stars-collisions-100701.html
>
> Some Ancient Stars In Milky Way Were Born Elsewhere
>
> By Zoe Macintosh
> SPACE.com Staff Writer
>
> posted: 01 July 2010
>
> Our Milky Way galaxy snatched up many of its most ancient stars from
> smaller galaxies that shredded each other in violent collisions, a new
> study suggests.
>
> Using new supercomputer simulations, researchers found that some ancient
> Milky Way stars did not form natively with the rest of the galaxy about 10
> billion years ago. Instead, they are actually the leftovers from other
> galaxies that collided about 5 billion years ago.
>
> These stars make up some of the residents in the Milky Way's stellar halo,
> which extends above and below the spiral galaxy's main disk, researchers
> said.
>
> "Effectively we became galactic archaeologists, hunting out the likely
> sites where ancient stars could be scattered around the galaxy," said
> researcher and post graduate student Andrew Cooper of the Institute of
> Computational Cosmology at Durham University in the United Kingdom.
>
> "Like ancient rock strata that reveal the history of Earth, the stellar
> halo preserves a record of a dramatic primeval period in the life of the
> Milky Way which ended long before the sun was born," he added.
>
> The new simulations began about 13 billion years ago, just after the
> universe began, and then used universal laws of physics to chart how the
> gravitational attraction of the galaxies' dark matter halos accumulated
> stars over time.
>
> Dark matter halos are regions of invisible matter around a galaxy which
> astronomers only infer exist because of their gravitational effects on
> visible matter.
>
> "The simulations are a blueprint for galaxy formation," said researcher
> Carlos Frenk, director of the Institute of Computational Cosmology at
> Durham.
>
> Frenk said the simulations reveal clues into the "early, violent history"
> of the Milky Way galaxy.
>
> Researchers credited the unusually high resolution of the new simulation
> for its results. Capable of zooming in on the fine details of galaxy
> unraveling, the simulations showed streams of stars being pulled from
> clusters due to the gravity of hidden dark matter.
>
> Most surprising was the similarity between the simulated results and real
> observations, said Cooper.
>
> "This shows that the cold dark matter model gives a convincing match to
> the real universe not just on very large scales, but also for individual
> Milky Way-like galaxies," he told SPACE.com.
>
> The cold dark matter model is the current "standard model" of cosmology,
> which depicts galaxy formation in the universe as a process primarily
> arising from the clumping of dark matter.
>
> The research is detailed in the journal Monthly Notices of the Royal
> Astronomical Society.
>
>
>
--
"If all the world's a stage and we are merely players, who the bloody hell
wrote the script?" -- Charles E Grant
http://www.youtube.com/watch?v=fQUxw9aUVik
