Study Details Bar at Center of Milky Way

[Kilik]

http://news.yahoo.com/s/ap/20050817/ap_on_sc/milky_way_bar

MADISON, Wis. - After creating the most detailed analysis yet of what the Milky Way looks like, astronomers say a long bar of stars cuts on an angle through the center of the galaxy that includes the sun and planet Earth.

Some scientists have suspected the presence of the stellar bar, but the survey led by two Wisconsin astronomers shows the bar is far longer than previously believed, and at a specific angle.
http://us.news3.yimg.com/us.i2.yimg.com/p/ap/20050816/capt.wimg50108161610.milky_way_study_wimg501.jpg?x =345&y=345&sig=zQhTNvzCAYu3ovh4oKplcg--

[Dr Adequate]

Study Details Bar at Center of Milky Way...

... and Restaurant at End of Universe.

[Lisa Simpson]

Geez, I thought everyone knew caramel is the center of the Milky Way.

[espritch]

I had heard some time ago that some scientists thought our galaxy was a bared spiral. I guess this vendicates that.

The question still remains as to why there are bared spiral galaxies at all. For a bar to exist, the stars on the ends of the bar have to be be orbiting the galactic center faster than the stars in the middle of the bar which is just about the opposite of what you would expect. I have yet to hear a good theory on why these form and what keeps the stars moving at just the right rate to maintain the bar structure.

[WildCat]

A long time ago, in a galaxy far, far away, this bar was pretty happening:

http://1001resources.com/hosting/users/cinesecrets/images/SW/SWCantina6%22+.jpg

Haven't been to the one in the center of our galaxy, unfortunately.:(

[c4ts]

Inside the stellar bar is stellar caramel and creamy nougat. But who hasn't already made that joke?

[Ducky]

/derail

What the heck is nougat anyway?

/derail off.

So my question is, are these then the axis that forces the spin of the milky way?

[Mongrel]

Originally posted by fowlsound
/derail

What the heck is nougat anyway?

/derail off.

So my question is, are these then the axis that forces the spin of the milky way?

/derail answer
Traditionally a gooey honey and nut confection (Recipe (http://www.milioni.com/ricingl/dati/519.htm)), commercially it's the claggy mess in the middle of your Snickers bar :)

/derail answer off

[Beth]

Originally posted by espritch
I had heard some time ago that some scientists thought our galaxy was a bared spiral. I guess this vendicates that.

The question still remains as to why there are bared spiral galaxies at all. For a bar to exist, the stars on the ends of the bar have to be be orbiting the galactic center faster than the stars in the middle of the bar which is just about the opposite of what you would expect. I have yet to hear a good theory on why these form and what keeps the stars moving at just the right rate to maintain the bar structure.

A good question, but how do we know that the bar structure is a long-lasting structure rather than a temporary (in galactic terms) one? Could it be something that occurs and then dissolves over a relatively short period of the galactic lifespan?

Beth

[SpaceFluffer]

Originally posted by espritch
The question still remains as to why there are bared spiral galaxies at all. For a bar to exist, the stars on the ends of the bar have to be be orbiting the galactic center faster than the stars in the middle of the bar which is just about the opposite of what you would expect. I have yet to hear a good theory on why these form and what keeps the stars moving at just the right rate to maintain the bar structure. Bars are thought to form because they represent a lower energy (and hence more stable) state for the galaxy. It seems that formation of a bar via transport of angular momentum is something that most galaxies (if not all) tend to do, if not interrupted in the process.

What makes this particularly interesting is that most galaxies do not have bars, and yet it seems that the vast majority should. The current thought is that the occurrence of a major merger event (a collision between galaxies of comparable size, and subsequent merging), in a time window between the galaxy's formation and some time before now, would stop the bar from forming. Since most galaxies go through a major merger at some point in their lifetime, this would explain why bars are not seen more often.

It's still up in the air to a certain extent though, because to be able to model this stuff effectively, you need to do complex many-body numerical simulations of both the stars and the dark matter. At the moment computing power limits us to resolution and object numbers smaller than we would like to be using.

[Beth]

Thanks SpaceFluffer. Interesting details I did not know before.

Beth

[Xeriar]

Don't let anyone tell you that the Milky Way is an average galaxy. It's not.

The Milky Way is one of very few galaxies that appears to have never suffered a major collision. It's central black hole is unusually small for its size (2.6 million Solar Masses where it should be close to a billion). Though 'only' 90 thousand light years in diameter (still bigger than most galaxies), it is one of the most massive spiral galaxies known at 1.9 trillion Solar Masses. I don't know if we'e found a galaxy that is denser, but I doubt it.

This is cool though. Regarding the stability of the bar, I also think it has to do with star formation.

[espritch]

The Milky Way is one of very few galaxies that appears to have never suffered a major collision.

The Andromeda galaxy is scheduled to remove that particular claim to uniqueness, a mere five billion years from now.

[Zep]

Originally posted by espritch
The Andromeda galaxy is scheduled to remove that particular claim to uniqueness, a mere five billion years from now. So I don't need to put out the trash this weekend??

[espritch]

So I don't need to put out the trash this weekend??

Well you could certainly try that excuse with the Missus, but I ain't betting she'll buy it.