Milky Way Discovered Embedded in a Colossal Halo of Gas --Equal to the Mass of All the Stars in the Galaxy
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September 26, 2012

Milky Way Discovered Embedded in a Colossal Halo of Gas --Equal to the Mass of All the Stars in the Galaxy

 

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The Chandra X-ray Telescope has provided evidence that our Milky Way Galaxy is embedded in an enormous halo of hot gas that extends for hundreds of thousands of light years, and is estimated to be comparable to the mass of all the stars in the Milky Way galaxy. If the size and mass of this gas halo is confirmed, it could be the solution to the "missing-baryon" problem for the Galaxy.

The artist's illustration above shows an enormous halo of hot gas (in blue) around the Milky Way galaxy. Also shown, to the lower left of the Milky Way, are the Small and Large Magellanic Clouds, two small neighboring galaxies (roll your mouse over the image for labels). The halo of gas is shown with a radius of about 300,000 light years, although it may extend significantly further.

Data from NASA's Chandra X-ray Observatory was used to estimate [link to press release] that the mass of the halo is comparable to the mass of all the stars in the Milky Way galaxy. If the size and mass of this gas halo is confirmed, it could be the solution to the "missing-baryon" problem for the Galaxy.

In a recent study, a team of five astronomers used data from Chandra, ESA's XMM-Newton, and Japan's Suzaku satellite to set limits on the temperature, extent and mass of the hot gas halo. Chandra observed eight bright X-ray sources located far beyond the Galaxy at distances of hundreds of millions of light years.

The data revealed that X-rays from these distant sources are selectively absorbed by oxygen ions in the vicinity of the Galaxy. The nature of the absorption allowed the scientists to determine that the temperature of the absorbing halo is between 1 million and 2.5 million Kelvins.

Other studies have shown that the Milky Way and other galaxies are embedded in warm gas, with temperatures between 100,000 and one million degrees, and there have been indications that a hotter component with a temperature greater than a million degrees is also present. This new research provides evidence that the mass in the hot gas halo enveloping the Milky Way is much greater than that of the warm gas.

The Daily Galaxy via Chandra X-Ray Observatory

Comments

The Milky Way is enshrouded in a gas cloud with a temperature of 1,000,000 Kelvin. In not a scientist, but intuitively this is a bit ludicrous. If it were really true, how could so many objects such as those in our solar system have such cool temperatures? There is something wrong with this picture.

the gas is too diffuse to have much effect on solar systems

so much for the mysterious dark matter. i thought that sounded like hokum. now lets see whats up w/ dark energy?

But how can this gas maintain indefinitely such hot temperature in an environment close to absolute zero?

There is probably only one explanation. The Milky Way's central power source (black hole) generates all this (as a protection vehicle) and sends energy to that gas to stay hot using circuitry that is presently beyond our understanding of the laws of physics.

Brad, vacuum is a heat insulator. The only way heat is transferred through vacuum is via radiation. Please learn your physics.

IMHO Dark matter is thr Flogiston or the Luminipherous Ether of this age.

Can this be the true Boundaries of our Universe??, and if So Welcome back Pluto???

Brad, 2 thinks that in perspective may help answer your question. Think about how diffuse the gas is. First lets think about how diffuse the milky way is. We have 100-200 billion stars sure but when we look out, we see maybe 1000 if we are lucky. This is because the milky way despite the large number of stars it is remarkable empty or at least empty-ish. Now look at the size of the gas and remember it has the same mass of the milky way, in the center, which looks very dense but in reality is very diffuse itself. So imagine something so thin/diffuse that we didn't even notice till now. Now think about how diffusion effects not temperature but heat transferred. I bet you can withstand a much higher temperature of something diffuse verses something dense. Want proof? Have you felt the air from the oven? It can be several hundred degrees but still nothing compared to what water would do to you at only 120F. So the high temperature would be fine. In fact excluding other factors, a person would not only not burn if they were on the corona or "surface" of the sun but they would actually freeze.

By "missing baryon" I assume they mean Dark Matter... right?

This debate on whether dark matter is real v.s. having wrong calculation and/or hidden baryonic matter has been going on for decades. Every so often another line of evidence goes on to support one or the other. For a while dark matter was the most supported in the debate, but for the last decade after scientists have been unable to detect any dark matter whatsoever and a few other theories coming about (of gas clouds and maybe dozens or hundreds of small and very hard-to-detect galaxies orbiting our own), it looks like the debate is back on in full-throttle.

Until we get conclusive evidence of one or the other, this problem won't be solved for at least another decade.

As a natural skeptic,I'm inclined to believe that Milky Way Scientist mix fact with fiction to get a rise out of folks. Some of the pics they post look like they were generated from Spielberg's "Dreamworks"! I'm just saying. Let's go back to Phiosophy 101 and start applying Occam's Razor ,shall we?

This solution to the 'missing' mass is a lot more 'believable' that the concept of dark matter and dark energy. Most solutions in nature follow the KISS method. Further study may find that all of the 'local group' is enveloped by this gas cloud and may provide the mass, and therefore gravity, that holds the group together.

Thank you for explaining my question. Highly appreciated.

Cullen, great answer to Brad Morton. Thanks for the insight.

This is the "missing baryon" problem, not the dark matter. Estimates place the amount of baryonic matter, not dark matter, to be around 2-3 times what is observed. The assumption has been that the material is in some form of non-luminous gas. This is evidence that the assumption is correct. Please note that if this was enough material to make up the mass difference needed for the dark matter it would be more like 15 times the mass of the observed Milky Way in gas. As for the temperature, you must understand that temperature is the result of atomic and molecular motion. If you have a very diffuse gas you can "heat", that means speed up, the particles to have high temperatures. They don't cool down because that requires the particles having something to collide with and transfer their energy to. Since the gas is diffuse collisions are rare. Finally, you don't bake in it because it is diffuse. Look up the solar corona. It is a gas halo around the sun which has temperature significantly greater then the surface of the sun. The effect is the same.

Is there friction in Space?

Jackal,
If there is matter, there is friction otherwise no friction in vaccum


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