I think so, here (hopefully my highly technical drawing isn't over anyones head):
the cloudy stuff? what is it and why are there so many dwarves in it? Is that just the oldest part of the galaxy and the top and bottom are newer?
Dwarf Spots
- Thread starter Murishani
- Start date
the cloudy stuff? what is it and why are there so many dwarves in it? Is that just the oldest part of the galaxy and the top and bottom are newer?
Yes we're talking about the same galactic dust. It's the coolest part of the Galaxy temperature wise, and that affects what kind of stars are likely to form there, but it's not necessarily the oldest structure. There is some debate as to which parts formed first (the halo or the bulge), which parts are cannibalized, and which parts arose from self organization. The reason the gas disk is flat is because it an amorphous rotating structure. Those tend to spin themselves flat like clay on a potters wheel as it condenses from 3D blob of gas. Stars rise above the plane because have a center of mass, and a velocity that can interact with other masses thus propelling them in orbits not unlike a horse on a merry-go-round soon after they form. This is also why open clusters of sister stars tend to fly apart and mix with other stars shortly after being formed.
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so the layer of dwarves inside the galactic dust at the cold "middle" of the disk is because the dwarves are lighter and didnt propel themselves merry go round style?
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Sort of. The short answer is that stars that are lighter tend to get knocked around more, and unless they are close to a massive object (like the galactic plane) then they are much more likely to get ejected from plane entirely.
Remember: F= G (M*m)/R^2, and F=ma
Where F is the force of gravity, G is a constant, M is the larger mass, m is the smaller mass, and a is the acceleration
Since both objects feel the same force, the smaller mass is accelerated (or decelerated) that much more.
One process that isn't precisely understood is what proportions the stars form in. The rarity of bigger stars points to the fact the smaller stars are easier to create, so there should generally be more of them for any star formation event. So perhaps a better question is, why don't we see more dwarfs outside the central disk? The answer depends on how stellar orbits around the core evolve. There are three possible outcomes for smaller lighter dwarfs:
1) They get captured by bigger stars, forming binaries
2) They get lightly "captured" by the plane itself (sort of like being mass locked to a planetary ring)
3) They get slung shot by larger stars, and gain enough velocity to escape the plane entirely and are "boiled" off into the Halo or intergalactic space.
right... have I mentioned I nearly failed algebra?
My guess is because they're all hiding behind much larger, brighter and more interesting hot stars.
THAT I understand, and point 1 lends itself to what we were talking about above. Basically, its in the middle because it wasnt captured by a larger star and thus harder to see without combing through galmap, and because it wasn't flung into the halo.
My logical mistake was confusing causation and correlation in that I was assuming that they were there because that was the logical place for them to go (i.e. migrate into), when the real answer is they're there because they started there (got lightly captured by the disk) and if they left that area, theyd have gotten captured or ejected.
Awesome stuff and I continue to be amazed by your knowledge on the subject, thank you for trying to educate me on the thing.
My canopy is busted, my paints chipped and my integrity is at 80~% I think I'm headed home.
If anyone has any further information on, or wants to participate in the dwarf field/spot discussion chime in.
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