Dark Matter Distribution Around Galaxies

In summary, the scientist described the dark matter halo around the milky way galaxy as having a squashed beachball-shaped shape. They think this might be caused by the rotating neutron stars that produce the magnetic fields around them. The concentration of dark matter in this shape has been proposed as a possible explanation for the presence of galactic black holes, but so far there is no evidence to support this theory.
  • #1
RLutz
20
0
I saw an interesting video that showed the dark matter halo that exists around the milky way galaxy, the scientist described it as having a squashed beached ball sort of shape, which got me thinking. Is there any reason why galactic black holes might have something to do with dark matter creation? The squashed beachball of dark matter sort of looks like what I would expect say field lines coming out of a pulsar to look like or something.

I guess what I'm getting at is, a rotating neutron star produces a magnetic field around it in something like a squashed beachball shape, is it plausible that the concentration of dark matter in squashed beachball shaped halos around galaxies have something to do with galactic black holes? Perhaps besides shooting out gamma rays they also shoot out strange particles that are only affected by gravity (dark matter)? I wish I knew more about the subject matter, but to me, the shape of the dark matter halo around the milky way really makes it look analogous to the shape of say magnetic field lines around a stellar body.

http://www.astronomy.ohio-state.edu/~ryden/ast162_5/pulsar.gif looks similar to
http://www.newscientist.com/article...ilky-ways-dark-matter-turned-on-its-side.html
 
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  • #2
Highly unlikely. The black holes at the centers of galaxies typically make up only a fraction of a percent to a couple percent of the total galaxy's mass, while the dark matter is typically around five to ten times as massive as all of the normal matter in the galaxy (including both stars and dust).

Furthermore, we see evidence of dark matter in the cosmic microwave background (CMB), which was emitted before any astrophysical black holes would have formed. Nobody has ever proposed, to my knowledge, a viable mechanism by which black holes could produce dark matter. Some have proposed that black holes could be dark matter, but that's ruled out by a number of different observations, including the CMB evidence.

Anyway, an elliptical shape is what we tend to expect from a bunch of non-interacting matter that falls into a potential well.
 
  • #3
Thanks!
 

1. What is dark matter and why is it important to study its distribution around galaxies?

Dark matter is a type of matter that does not interact with light, making it invisible to telescopes and difficult to detect. It is believed to make up about 85% of the total matter in the universe. Studying its distribution around galaxies is important because it can provide insights into the evolution and structure of our universe and help us understand the mysterious force of gravity that holds galaxies together.

2. How is the distribution of dark matter around galaxies measured?

The distribution of dark matter around galaxies is measured through a variety of methods, including gravitational lensing, which involves observing how the gravity of dark matter bends the light from distant galaxies; and studying the rotation curves of galaxies, which can reveal the presence of dark matter through its gravitational influence on the motion of stars and gas within the galaxy.

3. Are there any patterns or structures in the distribution of dark matter around galaxies?

Yes, there are observed patterns and structures in the distribution of dark matter around galaxies. These include dark matter halos, which are large spherical regions of dark matter that surround galaxies, and dark matter filaments, which are thin, web-like structures that connect galaxies and galaxy clusters.

4. How does the distribution of dark matter around galaxies compare to the distribution of visible matter?

The distribution of dark matter around galaxies is much more spread out and diffuse compared to the distribution of visible matter. While visible matter, such as stars and gas, is concentrated in the central regions of galaxies, dark matter is found in a much larger area, extending far beyond the visible boundaries of galaxies.

5. What are some current theories about the origin and nature of dark matter?

There are several theories about the origin and nature of dark matter, but the most widely accepted one is the Cold Dark Matter (CDM) model, which proposes that dark matter is made up of particles that move slowly and clump together due to gravity. Other theories include Modified Newtonian Dynamics (MOND), which suggests that gravity behaves differently on large scales, and the possibility that dark matter is a manifestation of extra dimensions in our universe.

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