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.
| Fast Facts for Abell 644: |
| Credit |
X-ray: NASA/CXC/Northwestern Univ/D.Haggard et al, Optical: SDSS |
| Release Date |
December 20, 2010 |
| Scale |
Image is 13.2 arcmin on a side (3.53 million light years)13.2 arcmin |
| Category |
Groups & Clusters of Galaxies Quasars & Active Galaxies |
| Coordinates (J2000) |
RA 08h 17m 25.6s | Dec -7° 30' 45'' |
| Constellation |
Hydra |
| Observation Date |
3/26/2001
|
| Observation Time |
8 hours 20 min |
| Obs. ID |
2211 |
| Instrument |
ACIS |
| References | Haggard, D. et al, 2010 ApJ 723:1447-1468 |
| Color Code |
X-ray (Blue), Optical (Red, Yellow, White) |
| Distance Estimate |
920 million light years (z=0.0701) |
|
| Fast Facts for SDSS J1021+1312: |
| Credit |
X-ray: NASA/CXC/Northwestern Univ/D.Haggard et al, Optical: SDSS |
| Release Date |
December 20, 2010 |
| Scale |
Image is 3.2 arcmin on a side (1.024 million light years)13.2 arcmin |
| Category |
Normal Galaxies & Starburst Galaxies Quasars & Active Galaxies |
| Coordinates (J2000) |
RA 10h 21m 47.86s | Dec +13° 12' 28.19'' |
| Constellation |
Hydra |
| Observation Date |
1/31/2003
|
| Observation Time |
2 hours 47 min |
| Obs. ID |
4107 |
| Instrument |
ACIS |
| References | Haggard, D. et al, 2010 ApJ 723:1447-1468 |
| Color Code |
X-ray (Blue), Optical (Red, Yellow, White) |
| Distance Estimate |
1.1 billion light years (z=0.085) |
|
To Back who asked how the galaxy got so far away: The Big Bang theory as it presently exists is said to have included a period of "hyperinflation" of the (small--then suddenly large) universe very early in its history.
In addition, measurements made about a decade ago showed that even now the expansion of the universe is continuously accelerating.
Posted by Leonard on Wednesday, 08.22.12 @ 00:36am
Hi Bach,
Actually the age of the universe as I have read in many books is close to 14 billion years old.
Interesting question though and hope it gets answered by one of the Chandra team.
Marvin L. S.
Posted by Marvin L. S. on Tuesday, 01.11.11 @ 21:28pm
I have a simple question. With all the talk about the universe having started with a massive explosion and it being ONLY 12 Billion years old? can some please explain the following deduction.
Let's take this galaxy 1.1 LY away. Let's also assume the objects exploded at an average speed of 10M mph. In order for this galaxy to get that far away from us would take it 720B years. How then can the universe be only 12 B years old? Appreciate an explanation
Posted by Bach on Friday, 01.7.11 @ 12:59pm
The article shows the payoff from synergistic usage of two sets of instrumentation. Great work.
Posted by Chris on Thursday, 12.23.10 @ 01:55am
Thank you for the great shots, wow very interesting, will stay open for all information.
Posted by rick moll on Wednesday, 12.22.10 @ 02:54am
What is very interesting is the difference between a cluster galaxy and field galaxy but a middle supermassive black hole, it don't depend on the quantity and type of mater eated, what kind of star make a massive black hole, white dwarf, red magnestar, neutron star, this observation may show us that a super black hole isn't an evolution from a new black hole but depend of primaries state.
Posted by PECQUERY on Tuesday, 12.21.10 @ 21:21pm
Of utmost importance. If the AGN in our Milky Way is active, its radiation could destroy lifeformes on planets on a large scale. May be also on earth. This means destruction could be possible apart from destruction due to events in our planetary system and on earth.
Posted by H van Astenrode on Tuesday, 12.21.10 @ 10:57am
That is most interesting. So, has our galaxy been active like this in its past according to the above information?
There is so much to learn, how Astronomy and Astrophysics has grown over the past Century. A very complex subject.
Marvin L. S.
Posted by Marvin L. S. on Monday, 12.20.10 @ 21:04pm