Is Dark Matter Present in the Milky Way Galaxy?

In summary, there is a belief that our solar system has a lower amount of dark matter compared to what is expected. The Milky Way, like other galaxies, has a normal amount of 80% dark matter and 20% baryonic matter. Recent calculations suggest that the dark matter mass in the solar system is less than 1.7 × 10-10 M ⊙, which is much smaller than Earth's mass. This is because dark matter cannot form clumps the size of the solar system, as it would result in significant changes in the galaxy.
  • #1
Tony Stark
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Is the presence of Dark Matter noted in Milky Way or somewhere around solar system??
 
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  • #2
Tony Stark said:
Is the presence of Dark Matter noted in Milky Way or somewhere around solar system??
I remember seeing (sorry, no citation) something about our solar system having a paucity of dark matter relative to what was believe to be likely. The milky way, as far as I know, is a normal galaxy and has about 80% dark matter, 20% boronic matter just like other galaxies.
 
  • #3
I believe you meant 20% baryonic matter
 
  • #4
jimgraber said:
I believe you meant 20% baryonic matter
Knowing me, I probably meant moronic. :smile:
 
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  • #5
If it didn't then it would've probably could not have held together also considering that the Milky Way can be small compared to other galaxies, so the answer to that would possibly be yes, or else it wouldn't hold together.
 
  • #6
The best credible recent calculation for dark matter mass in the solar system appears to be http://arxiv.org/abs/1306.5534, Constraints on Dark Matter in the Solar System, where it is asserted "The dark matter mass in the sphere within Saturn's orbit should be less than 1.7 × 10-10 M ⊙ even if its possible concentration is taken into account." To put this into perspective Earth's mass is about 3 × 10-6 M ⊙,
 
  • #7
Dark matter cannot form clumps (density inhomogeneities) the size of the solar system - average velocity of DM particles is too large for that.

We know that because if DM would be capable of doing that, the galaxy would look very different. For one, we'd see a large number of multiple star systems with "unseen mass" (IOW: systems where stars orbit way too fast). At least several percent of all multiple systems would show such effect. This is not observed.
 

Related to Is Dark Matter Present in the Milky Way Galaxy?

1. What is dark matter?

Dark matter is a type of matter that does not emit or interact with electromagnetic radiation, making it invisible to telescopes. It is estimated to make up about 85% of the total matter in the universe.

2. How do we know dark matter exists?

Scientists have observed the effects of dark matter through its gravitational pull on visible matter, such as stars and galaxies. Additionally, measurements of the cosmic microwave background radiation also support the existence of dark matter.

3. How much dark matter is there in the Milky Way?

It is estimated that about 85% of the matter in the Milky Way is dark matter. This means that there is approximately six times more dark matter than visible matter in our galaxy.

4. What is the role of dark matter in the formation of the Milky Way?

Dark matter played a crucial role in the formation and evolution of the Milky Way. Its gravitational pull helped to pull in gas and dust, which eventually formed into stars and galaxies. Without the presence of dark matter, the Milky Way would not have formed as it did.

5. What are scientists doing to study dark matter in the Milky Way?

Scientists are using various techniques, such as gravitational lensing and studying the rotation curves of galaxies, to try and understand the properties and distribution of dark matter in the Milky Way. Additionally, experiments are being conducted to directly detect and study dark matter particles.

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