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Fraser
2004-May-21, 05:21 PM
SUMMARY: M82, or the Starburst Galaxy, is one of the most studied galaxies in the night sky. New research from the University of Wisconsin-Madison has shed light on a cosmic hurricane that lives inside the galaxy, and sends out a stream of particles at more than 1.6 million km/h (1 million mph). These violent winds which go for thousands of light-years above and below the galaxy were caused because of M82's near miss with the neighboring spiral galaxy M81; this set off an explosive burst of star formation.

What do you think about this story? Post your comments below.

VanderL
2004-May-21, 08:29 PM
Well, interesting to see that there are vast streams of particles coming out of the heart of M82. What I have trouble understanding is how a near collision can produce two oppositely directed streams at high speed. This looks more like the jets coming from galaxies' cores, only on a different scale. Isn't this the process that is called ejection?

Cheers.

Duane
2004-May-21, 08:46 PM
The near miss caused material to move towards the SMBH. The jets are from material in the accretion disk that has been caught up in the jets.

antoniseb
2004-May-21, 09:20 PM
Originally posted by Duane@May 21 2004, 08:46 PM
The near miss caused material to move towards the SMBH. The jets are from material in the accretion disk that has been caught up in the jets.
No! The near miss disrupted the gas and dust clouds in the galaxy leading to a period of very rapid star formation and a very large number of supernovae. The clouds blowing material out of the galaxy are supernova shells blowing in all directions, but stopped by the galactic disk from spreading in the plane of the disk. This has little or nothing to do with the SMBH, or the jets. Something similar but on a much smaller scale can be seen in the LMC. There is a reason this is called the "Starburst Galaxy".

Duane
2004-May-21, 09:45 PM
I stand corrected :)

VanderL
2004-May-22, 11:26 AM
No! The near miss disrupted the gas and dust clouds in the galaxy leading to a period of very rapid star formation and a very large number of supernovae. The clouds blowing material out of the galaxy are supernova shells blowing in all directions, but stopped by the galactic disk from spreading in the plane of the disk.

Sounds a bit lame as an explanation; the part about the "near-miss" is pure conjecture, and this near-miss resulting in higher starburst activity is also a bit tenuous. Why not assume the galaxy is just very active and in the process of ejecting material?

Cheers.

Fraser
2004-May-22, 03:11 PM
It's the near miss that stirred up the stars and set up all the star formation. We see many active galaxies, which is happening because their supermassive black holes are in a feeding phase. They don't create the same star formation.

AnglesB
2004-May-25, 11:52 AM
M82 has always been a happy hunting ground. If I can see the pair of galaxies in the binoculars then I know I am in for a good observing session. My comment about the news item is the confusion of names that exist for M82. Ursa Major A or the Cigar galaxy were the names used up until a few years ago. Now we have all this activity being observed it becomes the Starburst galaxy.

Beginners must get very confused when they listen (or read) what the astronomers use when identifying objects. Star catalogues are even more confusing.

Andy