Dark Matter Distribution in the Milky Way

[mersecske]

What is our best knowledge on the mass and spatial distribution of dark matter in our galaxy?
Could you give me a good reference?

 

[phinds]

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.

 

[Vagn]

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" suggests that dark matter in the Milky Way has a mass of the order of 10¹² solar masses though.

 

[mersecske]

Do we know something about the forces between dark matter particles? Some restriction in some models?

 

[bapowell]

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.

 

[mersecske]

Or it is possible to be an unknown interaction?

 

[Chalnoth]

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.