Comments on: Desktop Project Part 25: Chaos in a galactic nursery http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/ Wed, 21 Nov 2012 15:12:45 +0000 hourly 1 http://wordpress.org/?v=3.4.2 By: Infinite123Lifer http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328805 Infinite123Lifer Fri, 20 Apr 2012 01:23:07 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328805 I suppose taking me away from the Universe is akin to subtracting 1 from infinity, though it may show up in the calculation, its/I am more of just a nuisance ;) I suppose taking me away from the Universe is akin to subtracting 1 from infinity, though it may show up in the calculation, its/I am more of just a nuisance ;)

]]> By: Infinite123Lifer http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328804 Infinite123Lifer Fri, 20 Apr 2012 01:05:19 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328804 "The Universe doesn’t care very much what you think, and will continue to behave according to the laws of nature. We’re the ones who have to change and adapt to what it’s telling us." Hey wait, I thought I was part of the Universe? ;) Oh, you mean the rest of the Universe doesn't care what I think . . . very much. :) Indubitably Dr. Plait, indubitably. “The Universe doesn’t care very much what you think, and will continue to behave according to the laws of nature. We’re the ones who have to change and adapt to what it’s telling us.”

Hey wait, I thought I was part of the Universe? ;)

Oh, you mean the rest of the Universe doesn’t care what I think . . . very much. :) Indubitably Dr. Plait, indubitably.

]]> By: JR http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328803 JR Thu, 19 Apr 2012 20:33:12 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328803 To be nitpickily specific: starburst driven outflows receive a significant fraction of their energy and momentum from Supernovae, not just from stellar winds. From Veilleux's 2005 review of galactic winds: "In general, stellar winds are important only in young (10^7 yr) starbursts that form many high-mass (60 Mo) stars in a metal-rich (Z>Zo) environment. In any other situation, SN explosions dominate the energetics of the ISM. SN explosions usually dominate by the time GWs develop, but stellar winds may be important in superbubbles." Links for further reading: http://astronomy.swin.edu.au/cosmos/G/Galactic+Winds http://www.universetoday.com/9056/galactic-wind-connects-galaxies/ References for people who like that sort of thing (Besides the 1700 articles about M82 itself): http://adsabs.harvard.edu/abs/2005ARA%26A..43..769V http://adsabs.harvard.edu/abs/1998ApJ...493..129S http://adsabs.harvard.edu/abs/2010ApJ...711..818S http://adsabs.harvard.edu/abs/2010ApJ...721..505R To be nitpickily specific: starburst driven outflows receive a significant fraction of their energy and momentum from Supernovae, not just from stellar winds. From Veilleux’s 2005 review of galactic winds:

“In general, stellar winds are important only in young (10^7 yr) starbursts that form many high-mass (60 Mo) stars in a metal-rich (Z>Zo) environment. In any other situation, SN explosions dominate the energetics of the ISM. SN explosions usually dominate by the time GWs develop, but stellar winds may be important in superbubbles.”

Links for further reading:
http://astronomy.swin.edu.au/cosmos/G/Galactic+Winds
http://www.universetoday.com/9056/galactic-wind-connects-galaxies/

References for people who like that sort of thing
(Besides the 1700 articles about M82 itself):
http://adsabs.harvard.edu/abs/2005ARA%26A..43..769V
http://adsabs.harvard.edu/abs/1998ApJ…493..129S
http://adsabs.harvard.edu/abs/2010ApJ…711..818S
http://adsabs.harvard.edu/abs/2010ApJ…721..505R

]]> By: xmundt http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328802 xmundt Thu, 19 Apr 2012 19:30:41 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328802 Greetings and Salutations; Well, it is my understanding that the gases have been heated to several million degrees....but...the fact that their density is so low means that it is not exactly WARM in the middle of the cloud. Got to remember that "temperature" is a function of the amount of energy imparted to the molecules, so, a Hydrogen atom bouncing around at a high speed because of the energy imparted to it from the radiation produced by star formation, is "warmer" than one that is just barely moving because it has no external source of energy... IANAP, so, if Dr. Plait or one of the many other readers who are far more knowledgeable about the subject want to chime in, I would welcome the input! pleasant dreams dave mundt . Greetings and Salutations;
Well, it is my understanding that the gases have been heated to several million degrees….but…the fact that their density is so low means that it is not exactly WARM in the middle of the cloud. Got to remember that “temperature” is a function of the amount of energy imparted to the molecules, so, a Hydrogen atom bouncing around at a high speed because of the energy imparted to it from the radiation produced by star formation, is “warmer” than one that is just barely moving because it has no external source of energy…
IANAP, so, if Dr. Plait or one of the many other readers who are far more knowledgeable about the subject want to chime in, I would welcome the input!
pleasant dreams
dave mundt
.

]]> By: Charlie http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328801 Charlie Thu, 19 Apr 2012 17:45:12 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328801 How warm are we talking when you say "warm hydrogen"? I assume it is still pretty cold compared to our comfy 20 C. How warm are we talking when you say “warm hydrogen”? I assume it is still pretty cold compared to our comfy 20 C.

]]> By: xmundt http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328800 xmundt Thu, 19 Apr 2012 15:37:05 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328800 Greetings and Salutations. First off, I agree 100% with Sherry Austin. While the same thought has been expressed by others, in somewhat different words, that is a very cogent way of putting out how the Universe works. For that matter it works whether one is speaking of the Macro scale of Galactic Interactions or the Micro scale of some of the odd interactions of sub-atomic particles. As for the picture that is the center of the thought here...I have to say that the higher resolution pictures do make it clearer that the plumes of warm hydrogen are coming from inside the spiral galaxy. Years ago, when I first saw less detailed images of this event, it looked to me as if this was more on the order of some sort of plume of the gas superimposed on the image of the galaxy. More information is always better than less information, even if it DOES force one to reconsider basic beliefs... Pleasant Dreams dave mundt Greetings and Salutations.
First off, I agree 100% with Sherry Austin. While the same thought has been expressed by others, in somewhat different words, that is a very cogent way of putting out how the Universe works. For that matter it works whether one is speaking of the Macro scale of Galactic Interactions or the Micro scale of some of the odd interactions of sub-atomic particles.
As for the picture that is the center of the thought here…I have to say that the higher resolution pictures do make it clearer that the plumes of warm hydrogen are coming from inside the spiral galaxy. Years ago, when I first saw less detailed images of this event, it looked to me as if this was more on the order of some sort of plume of the gas superimposed on the image of the galaxy. More information is always better than less information, even if it DOES force one to reconsider basic beliefs…
Pleasant Dreams
dave mundt

]]> By: mike http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328799 mike Thu, 19 Apr 2012 15:28:34 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328799 Nice image. Definitely one of my favorite galaxies - both because it looks so cool framed together with M81 in a small telescope, and also because of all that seems to be happening there (including "apparently superluminal" microquasars http://www.newscientist.com/article/dn18775-mysterious-radio-waves-emitted-from-nearby-galaxy.html ) Nice image. Definitely one of my favorite galaxies – both because it looks so cool framed together with M81 in a small telescope, and also because of all that seems to be happening there (including “apparently superluminal” microquasars http://www.newscientist.com/article/dn18775-mysterious-radio-waves-emitted-from-nearby-galaxy.html )

]]> By: Sherry Austin http://blogs.discovermagazine.com/badastronomy/2012/04/19/desktop-project-part-25-chaos-in-a-galactic-nursery/#comment-328798 Sherry Austin Thu, 19 Apr 2012 14:13:53 +0000 http://blogs.discovermagazine.com/badastronomy/?p=46957#comment-328798 "The Universe doesn’t care very much what you think, and will continue to behave according to the laws of nature. We’re the ones who have to change and adapt to what it’s telling us." Well said. “The Universe doesn’t care very much what you think, and will continue to behave according to the laws of nature. We’re the ones who have to change and adapt to what it’s telling us.” Well said.

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