First Invisible Galaxy Discovered in Cosmology Breakthrough

[Herbaholic00]

http://www.gnn.tv/headlines/1228/Fir...y_Breakthrough


Astronomers have discovered the first known galaxy made of dark matter.


Astronomers have discovered an invisible galaxy that could be the first of many that will help unravel one of the universeâ??s greatest mysteries.

The object appears to be made mostly of dark matter, material of an unknown nature that canâ??t be seen.

Theorists have long said most of the universe is made of dark matter. Its presence is required to explain the extra gravitational force that is observed to hold regular galaxies together and that also binds large clusters of galaxies.

Theorists also believe knots of dark matter were integral to the formation of the first stars and galaxies. In the early universe, dark matter condensed like water droplets on a spider web, the thinking goes. Regular matterâ??mostly hydrogen gasâ??was gravitationally attracted to a dark matter knot, and when the density became great enough, a star would form, marking the birth of a galaxy.

The theory suggests that pockets of pure dark matter ought to remain sprinkled across the cosmos. In 2001, a team led by Neil Trentham of the University of Cambridge predicted the presence of entire dark galaxies.

One of perhaps many

The newfound dark galaxy was detected with radio telescopes. Similar objects could be very common or very rare, said Robert Minchin of Cardiff University in the UK.

â??If they are the missing dark matter halos predicted by galaxy formation simulations but not found in optical surveys, then there could be more dark galaxies than ordinary ones,â?� Minchin told SPACE.com.

In a cluster of galaxies known as Virgo, some 50 million light-years away, Minchin and colleagues looked for radio-wavelength radiation coming from hydrogen gas. They found a well of it that contains a hundred million times the mass of the Sun. It is now named VIRGOHI21.

The well of material rotates too quickly to be explained by the observed amount of gas. Something else must serve as gravitational glue.

â??From the speed it is spinning, we realized that VIRGOHI21 was a thousand times more massive than could be accounted for by the observed hydrogen atoms alone,â?� Minchin said. â??If it were an ordinary galaxy, then it should be quite bright and would be visible with a good amateur telescope.â?�

The ratio of dark matter to regular matter is at least 500-to-1, which is higher than I would expect in an ordinary galaxy,â?� Minchin said. â??However, it is very hard to know what to expect with such a unique objectâ??it may be that high ratios like this are necessary to keep the gas from collapsing to form stars.â?�

Long road to discovery

Other potential dark galaxies have been found previously, but closer observations revealed stars in the mix. Intense visible-light observations reveal no stars in VIRGOHI21.

The invisible galaxy is thought to lack stars because its density is not high enough to trigger star birth, the astronomers said.

The discovery was made in 2000 with the University of Manchesterâ??s Lovell Telescope, and the astronomers have worked since then to verify the work. It was announced today.
â??The universe has all sorts of secrets still to reveal to us, but this shows that we are beginning to understand how to look at it in the right way,â?� said astronomer Jon Davies of Cardiff University in the UK. Itâ??s a really exciting discovery.â?�

Additional radio observations were made with the Arecibo Observatory in Puerto Rico. Follow-up optical work was done with the Isaac Newton Telescope in La Palma. Astronomers from the UK, France, Italy and Australia contributed to the research. The project is now searching for other possible dark galaxies.

Dark matter makes up about 23 percent of the universeâ??s mass-energy budget. Normal matter, the stuff of stars, planets and people, contributes just 4 percent. The rest of the universe is driven by an even more mysterious thing called dark energy.




Peace

Herbaholic00 Reviewed by Herbaholic00 on 02-24-2005. First Invisible Galaxy Discovered in Cosmology Breakthrough http://www.gnn.tv/headlines/1228/First_Invisible_Galaxy_Discovered_in_Cosmology_Breakthrough Astronomers have discovered the first known galaxy made of dark matter. Astronomers have discovered an invisible galaxy that could be the first of many that will help unravel one of the universeâ??s greatest mysteries. The object appears to be made mostly of dark matter, material of an unknown nature that canâ??t be seen. Rating: 5

[kronick]

interesting...

[naturalmystic]

Very.

[kronick]

i love it when scientists find new shit out.(even if they are wrong) gives you something to think about.

[Herbaholic00]

I read some where that some people have the theory that the same % of the brain that we dont use is the same % of the universe that we dont know about or something like that. There is so much shit we dont even slightly understand. It all has strong reaching implications for us all tho tho, immagine if something like string theory and paralel universe type stuff was proven (not sayin i believe it). Do you think religion would ever be looked at in the same way again...it crazy.



Peace

[kronick]

I read some where that some people have the theory that the same % of the brain that we dont use is the same % of the universe that we dont know about or something like that.

i dont think there is a relation between the 2 at all.

There is so much shit we dont even slightly understand. It all has strong reaching implications for us all tho tho, immagine if something like string theory and paralel universe type stuff was proven (not sayin i believe it). Do you think religion would ever be looked at in the same way again...it crazy.

if some of these theories were proved to be true...religions would definatly look at things differently but just remember when that guy (w.e the frig his name was)proved the earth was round...all the religions said "noooo you are wrong!! the earth is flat and we are the centre of everything cause we're stuck up narcissistic bastards!" showed them eh? so untill they accept something like that...its gonna be a long hard road but i dont think anything in this reality can prove or disprove the existance of god...well unless...a divine intervention occurs. im still waiting on that one....and so is the rest of the world. well, one other thing "can possiably" prove against god. the existance of alians. who i think do exist...seeing as how HUGE the universe is...and to think humans are the only assentient life, is ignorant and stupid.

[GHoSToKeR]

the same % of the brain that we dont use is the same % of the universe that we dont know about

I don't think there's any correlation. We only know about small percentage of the universe, and most of what we know is just supposition. There's still so much that we don't even know about the human body and the Earth itself.

[kronick]

I don't think there's any correlation.

i believe i already stated that...but in other words

[GHoSToKeR]

yup, you did.. i was stating my opinion, also

[Herbaholic00]

the same % of the brain that we dont use is the same % of the universe that we dont know about

I dont buy it either lol, sounds like some david icke shit.



Peace