Post by Bozur on Oct 3, 2005 18:03:18 GMT -5
Findings
Virgo Offers a Peek at the Violent History of the Galaxies Next Door
By DENNIS OVERBYE
Published: September 27, 2005
In a telescope or in ordinary pictures that capture a cosmic instant, the 2,000 or so galaxies of the Virgo cluster glow like pearly city-states, isolated and smug agglomerations of starlight. But astronomers know these galaxies are really buzzing about like bees confined by gravity in a hive some 10 million light-years across, careering back and forth at 500 miles a second, banging into one another and splashing stars and gas across space.
Chris Mihos
Astronomers from Case Western Reserve University in Cleveland say they have now found a sort of archaeological record of this violent and chaotic aspect of the life of galaxies in the form of streaks in the sky.
An ultrasensitive photograph of the heart of the Virgo cluster shows the galaxies there enmeshed in a complex web of diffuse faint streams of starlight. The streams, they say, are made up of stars that were ripped from their galaxies in collisions in the building of the cluster.
The Virgo cluster, with a mass of at least 100 trillion Suns, is the biggest thing in the local cosmic neighborhood. The appearance of the streams suggests that it is still being assembled, said Dr. J. Christopher Mihos, an astronomer at Case Western who led the team that did the work. "It does not really look like a system that has been around for billions of years," Dr. Mihos said.
They published their results in the Sept. 20 issue of Astrophysical Journal Letters.
The astronomers hope that eventually better observations of the streamers, along with computer simulations, will allow them to reconstruct the process by which the giant cluster was built and is continuing to be built. The process is relevant to our own future.
At a distance of about 50 million light-years, the Virgo cluster is next door, cosmically speaking, to our own galaxy, the Milky Way, and its gravity is strong enough to have retarded slightly the expansion of the universe in our neighborhood.
As a result, sometime, perhaps billions of years from now, astronomers say, depending on the evolution of the dark energy pushing space-time apart, it is possible that our galaxy will succumb to Virgo's pull and go crashing through the fat galaxies sitting like spiders at its center. Then the Milky Way's contents, including whatever remains of our Sun and its innocent retinue, would be left splashed and smeared like pale graffiti across some alien sky.
Virgo Offers a Peek at the Violent History of the Galaxies Next Door
By DENNIS OVERBYE
Published: September 27, 2005
In a telescope or in ordinary pictures that capture a cosmic instant, the 2,000 or so galaxies of the Virgo cluster glow like pearly city-states, isolated and smug agglomerations of starlight. But astronomers know these galaxies are really buzzing about like bees confined by gravity in a hive some 10 million light-years across, careering back and forth at 500 miles a second, banging into one another and splashing stars and gas across space.
Chris Mihos
Astronomers from Case Western Reserve University in Cleveland say they have now found a sort of archaeological record of this violent and chaotic aspect of the life of galaxies in the form of streaks in the sky.
An ultrasensitive photograph of the heart of the Virgo cluster shows the galaxies there enmeshed in a complex web of diffuse faint streams of starlight. The streams, they say, are made up of stars that were ripped from their galaxies in collisions in the building of the cluster.
The Virgo cluster, with a mass of at least 100 trillion Suns, is the biggest thing in the local cosmic neighborhood. The appearance of the streams suggests that it is still being assembled, said Dr. J. Christopher Mihos, an astronomer at Case Western who led the team that did the work. "It does not really look like a system that has been around for billions of years," Dr. Mihos said.
They published their results in the Sept. 20 issue of Astrophysical Journal Letters.
The astronomers hope that eventually better observations of the streamers, along with computer simulations, will allow them to reconstruct the process by which the giant cluster was built and is continuing to be built. The process is relevant to our own future.
At a distance of about 50 million light-years, the Virgo cluster is next door, cosmically speaking, to our own galaxy, the Milky Way, and its gravity is strong enough to have retarded slightly the expansion of the universe in our neighborhood.
As a result, sometime, perhaps billions of years from now, astronomers say, depending on the evolution of the dark energy pushing space-time apart, it is possible that our galaxy will succumb to Virgo's pull and go crashing through the fat galaxies sitting like spiders at its center. Then the Milky Way's contents, including whatever remains of our Sun and its innocent retinue, would be left splashed and smeared like pale graffiti across some alien sky.