Thread: Shape of our galactic bulge

Somewhere along the line somebody or something told me that the Milky-way's central bulge is bar shaped. It is hard to fancy that. Since no humans have viewed the bulge from anywhere near along the galactic axis, then reason would have it that the bar shape might just be hypothetical. The mere departure from radial symmetry is disturbing. A little help?

Golly, maybe the bulge has simply somehow been sensed to have grown a little and has been mistaken for turning a broadside to us as we orbit around it.

http://en.wikipedia.org/wiki/Barred_spiral_galaxy

I have the impression that the question was not, if bars in spiral galaxies actually exist. I think it was more going into the direction of what evidence there is that our Milky Way has a bar shaped bulge. I found a few references that might help:

http://www.newscientist.com/article/...-revealed.html
http://www.solstation.com/x-objects/cenbulge.htm
http://www.daviddarling.info/encyclopedia/G/Galaxy.html
http://en.wikipedia.org/wiki/Milky_Way

The central publication containing the latest results is available only to subscribed affiliations. I have made it available at:
ftp://ftp.mpia.de/pub/nielbock/Publi...13_GLIMPSE.pdf

The basic technique is to count stars being at certain distances. With these data, you can produce a very accurate map of the Milky Way. We know from other galaxies that the stellar content in bars is dominated by an old and red population that can be best observed at infrared wavelengths.

It interesting - correct me if necessary Dishmaster - that this recent discovery of the barred character of our galaxy is one of many such breakthroughs that have emerged over the last couple of decades as a result of the revolution in instrumentation: satellite telescopes that can observe the universe in wavelengths that are blanketed by the Earth's atmosphere and increasingly sophisiticated ground based equipment. (And on a more local level the various planetary probes within our own system.) The depth and breadth of our understanding has changed dramatically in the five decades during which I have had an interest in the field.

Originally Posted by Dishmaster

I have the impression that the question was not, if bars in spiral galaxies actually exist. I think it was more going into the direction of what evidence there is that our Milky Way has a bar shaped bulge. I found a few references that might help:

Right on. Appreciate the help. Newfound knowledge resulting has set me free. Thinking now that the bar is simply feeding upon a single strand of stars amidst of which it is positioned. It all makes sense again.