This artist's illustration 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 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.
|
Many of your questions in the comments are being answered in this blog article http://www.chandra.si.edu/blog/node/399.
Posted by CXC on Thursday, 10.4.12 @ 10:47am
After about 35 yrs, mans inventions have only reached the outer part of our solar system, which doesn't even feature in the scale of the image. The vastness of this bubble is mind-blowing. I am wondering if this gas is perhaps leftover from when our galaxy formed. If the M.W. has this halo - bubble, it stands to reason that other galaxies should have it also. Perhaps this is where a lot of the missing mass is placed. I wonder if Captain Kirk knew about this ?
Posted by Ray Murray on Thursday, 10.4.12 @ 05:42am
I think this shows how a narrow view of the cosmos can lead to poor assumptions. 20 yrs ago I-galactic space had1 atom/cu.m, now what else will we find !
Posted by Mike on Wednesday, 10.3.12 @ 17:59pm
Interesting finding. To what extent may the halo correlate to magnetic fields and to plasmas between galaxies?
Posted by David Harrison on Tuesday, 10.2.12 @ 11:05am
How exciting this news is! A great tribute to all the astronomers from Galileo to S. Chandrasekhar.
Posted by G N Viswanath on Saturday, 09.29.12 @ 11:50am
The Halo of gas of 300,000 light years radius, I wonder could it be the missing dark matter?
Posted by sunderajan on Saturday, 09.29.12 @ 10:52am
Wow, A1
Posted by Anton Doppler on Saturday, 09.29.12 @ 10:24am
This is quite a revelation. That our milky way is engulf in hot gas. Please, keep it up.
Posted by Godwin Idemudia on Saturday, 09.29.12 @ 02:35am
A fascinating, and in some ways comforting finding, possibly solving the baryonic issue.
Posted by Mitchell Dormont on Friday, 09.28.12 @ 12:53pm
What is heating up all this interstellar matter to such high temperatures? Considering its vicinity, shouldn't it actually be only a few degrees above absolute zero?
Also, maybe it's not really a halo but rather us looking from inside a pocket of empty space formed in the nebula from which our galaxy once coalesced.
Posted by Saud on Thursday, 09.27.12 @ 11:28am
Are there any implications of this new data that could change how we look at Dark Matter or Dark Energy?
Posted by Fernando Sanchez on Wednesday, 09.26.12 @ 21:15pm
So, Here are some dumb questions from a lay person... Is this the mysterious "dark matter" we have been looking for? Why is it so hot? Is "dark energy" simply Boyle's law on a cosmic scale? This is an outstanding discovery and a much nicer solution to the missing mass in the universe than the "dark matter" voodoo.
Posted by Jason on Wednesday, 09.26.12 @ 16:42pm
Is the heating mechnism of that hot gas halo are the compact X-ray source objects or something else? I belive without heating it should have lost already since long time its energy via dissipative radiation.
Posted by Attila on Wednesday, 09.26.12 @ 08:25am
Awesome, so exciting information... thanks for your information. Go ahead, we are with you.
Posted by Sanjit Kumar Bandyopadhyay on Wednesday, 09.26.12 @ 06:51am
This is very interesting, I am curious about how this cloud of gas is producing so much heat?
Posted by Stephen on Tuesday, 09.25.12 @ 21:02pm
How and where does the heat come from?
Posted by Jim Fisher on Tuesday, 09.25.12 @ 07:48am
Very interesting indeed! One question though, if we (our galaxy) are within a Halo of hot gas of very high temperature, why are the temperature beyond Earth's atmosphere, so low. Kindly explain.
Posted by Souma Datta on Tuesday, 09.25.12 @ 06:05am
I have read somewhere on a NASA web page that our the Milky Way Galaxy is about 100,000 LY in diameter. If that is so, then the drawing above is not to scale. I count between 6 and 7 Milky Way diameters for the cloud's radius.
Posted by Odo Siahaya on Monday, 09.24.12 @ 19:22pm
Awsome! But how much does the estimates of the halo take up the 'lost mass' of the cosmos? If it has the equavelent of one galaxy, that isn't much...
Posted by Stark on Monday, 09.24.12 @ 18:46pm
Very exciting! Galactic rotation curves (velocity of rotation versus the distance from the galactic center) can not be explained by only the visible matter. The current best theory is that galaxies are composed largely of a roughly spherically symmetric halo of dark matter with the visible matter concentrated in a disc at the center. Can the observed rotation curves be fully accounted for by such a baryonic (not dark matter) halo of similar magnitude in other galaxies?
Posted by Publius on Monday, 09.24.12 @ 15:50pm
This is a magnificent discovery. What I would like to ask is how this massive gas halo will effect the planet earth and sun during the winter soltice and when the planets are aligned with the Milky Way galaxy?
Posted by Pamela Greenfield on Monday, 09.24.12 @ 14:23pm