Dark Matter Distribution in the Milky Way

In summary, our current understanding is that dark matter makes up around 25% of the matter in the universe, with normal matter accounting for about 5% and dark energy making up the remaining 70%. In our galaxy, dark matter is distributed evenly and makes up the majority of its mass. While there is no definitive reference on hand, numerous sources on the internet can provide further information. The interaction between dark matter particles is believed to be primarily gravitational, but there is still uncertainty and the possibility of unknown interactions.
  • #1
mersecske
186
0
What is our best knowledge on the mass and spatial distribution of dark matter in our galaxy?
Could you give me a good reference?
 
Space news on Phys.org
  • #2
Dark matter makes up about 25% of the matter in the U, normal matter about 5%, and dark energy about 70%. Dark matter is clumped on a large scales (somewhat larger than the galaxies it surrounds, which I think is ALL galaxies, and little or none in intergalactic space) but seems to be very homogeneous on small scale (near and in the galaxies).

I don't have a good ref on hand but the Inet is full of them. Try wikipedia.
 
  • #3
Dark matter is distributed fairly evenly throughout the galaxy and makes up the majority of the mass of the Milky Way. I've seen figures ranging between about 70% and 90% of the Milky Way's mass being composed of dark matter, although I can't find an academic reference. http://arxiv.org/PS_cache/astro-ph/pdf/0506/0506102v2.pdf" [Broken] suggests that dark matter in the Milky Way has a mass of the order of 1012 solar masses though.
 
Last edited by a moderator:
  • #4
Do we know something about the forces between dark matter particles? Some restriction in some models?
 
  • #5
mersecske said:
Do we know something about the forces between dark matter particles? Some restriction in some models?
The interaction between dark matter particles must be predominantly gravitational. Dark matter does not participate in the electromagnetic interaction, but it might participate in the weak interaction.
 
  • #6
Or it is possible to be an unknown interaction?
 
  • #7
mersecske said:
Or it is possible to be an unknown interaction?
Yes. As long as we still haven't detected the dark matter particle, its properties are fairly up in the air. But in any case the interactions must be pretty weak, whatever they are.
 

1. What is dark matter and why is it important to study its distribution in the Milky Way?

Dark matter is a type of matter that does not emit or absorb light, making it invisible to traditional telescopes. However, its presence can be inferred through its gravitational effects on visible matter. It is important to study its distribution in the Milky Way because it makes up about 85% of the total matter in the universe and plays a crucial role in the formation and evolution of galaxies.

2. How do scientists determine the distribution of dark matter in the Milky Way?

Scientists use various techniques, such as gravitational lensing, rotation curves, and simulations, to map the distribution of dark matter in the Milky Way. Gravitational lensing occurs when the gravity of dark matter bends the path of light from distant galaxies, providing clues about its location and density. Rotation curves measure the speed of stars and gas in the galaxy, which can also reveal the presence of dark matter. Simulations use computer models to estimate the distribution of dark matter based on its gravitational effects.

3. What is the current understanding of the distribution of dark matter in the Milky Way?

Based on current research, scientists believe that dark matter is distributed in a spherical halo around the Milky Way's central disk. The density of dark matter is highest in the center of the galaxy and decreases as you move towards the outskirts. However, the exact distribution and density are still debated and continue to be studied.

4. How does the distribution of dark matter affect the dynamics of the Milky Way galaxy?

The presence of dark matter significantly affects the dynamics of the Milky Way galaxy. Its gravitational pull helps hold the galaxy together and prevents stars and gas from escaping. It also plays a crucial role in the formation and evolution of structures within the galaxy, such as spiral arms and the central bulge.

5. What are the implications of studying the distribution of dark matter in the Milky Way for our understanding of the universe?

Studying the distribution of dark matter in the Milky Way not only helps us understand the dynamics of our own galaxy, but it also has implications for our understanding of the universe as a whole. By studying the distribution of dark matter in different galaxies, we can gain insights into the large-scale structure and evolution of the universe. It may also provide clues about the nature of dark matter and its role in the formation and evolution of galaxies and the universe.

Similar threads

Replies
4
Views
872
  • Cosmology
Replies
14
Views
1K
  • Cosmology
Replies
13
Views
1K
Replies
10
Views
999
Replies
19
Views
550
Replies
23
Views
1K
Replies
3
Views
1K
Replies
5
Views
306
Replies
12
Views
2K
  • Cosmology
Replies
4
Views
1K
Back
Top