Dust vs Suns: Exploring the Abundance of Dark Matter in Space

[ClamShell]

I guess dark matter is the most abundant
matter. But which contributes next to the
most, intersteller dust or suns?

 

[Chalnoth]

I guess dark matter is the most abundant
matter. But which contributes next to the
most, intersteller dust or suns?

Mostly intergalactic dust, actually. This is especially the case for galaxy clusters, where there is something like ten times as much mass in the cluster gas as there is in stars.

I'm not entirely sure what the breakdown is for individual galaxies outside of clusters, though.

 

[ClamShell]

Mostly intergalactic dust, actually. This is especially the case for galaxy clusters, where there is something like ten times as much mass in the cluster gas as there is in stars.

I'm not entirely sure what the breakdown is for individual galaxies outside of clusters, though.

Does anyone have a current value for the ratios?

Say for every gram of stars there might be 3 grams
of dust and 10 grams of dark matter(mass?)

IE, 1 : 3 : 10

 

[phyzguy]

I think you're confusing the terminology. In astrophysics parlance, "dust" refers to elements heavier than helium. Most of the baryon mass of a galaxy or a cluster is in interstellar or intergalactic gas, not dust. I don't have exact figures, but I think for a large galactic cluster, the numbers are roughly dark matter about 80%, baryons about 20%, and the baryons break down about 95% gas, 2% dust and 2% stars, so the total would be about 80% dark matter, 18% gas, 1% dust and 1% stars.

 

[ClamShell]

I think you're confusing the terminology. In astrophysics parlance, "dust" refers to elements heavier than helium. Most of the baryon mass of a galaxy or a cluster is in interstellar or intergalactic gas, not dust. I don't have exact figures, but I think for a large galactic cluster, the numbers are roughly dark matter about 80%, baryons about 20%, and the baryons break down about 95% gas, 2% dust and 2% stars, so the total would be about 80% dark matter, 18% gas, 1% dust and 1% stars.

Arrrggghhh, I just learned something; gas(H & He) is not dust;
should have known. The "dust" is the stuff we are made of.
(mainly C, H, O, N, P, Fe & S...)
I assume that where there is dust, there must have been a
supernova since "dust" seems to have been created inside
stars. Is the "dust" everywhere?

 

[phyzguy]

The supernovae seem to stir things up pretty good, so the data says the elemental abundances are pretty uniform. Attached is a good paper on this. In the solar neighborhood, this paper says that the interstellar medium is 71.5% H, 27.1% He, and 1.4% everything else, with O and C being the most abundant elements heavier then He.

 

[ClamShell]

The supernovae seem to stir things up pretty good, so the data says the elemental abundances are pretty uniform. Attached is a good paper on this. In the solar neighborhood, this paper says that the interstellar medium is 71.5% H, 27.1% He, and 1.4% everything else, with O and C being the most abundant elements heavier then He.

Does the big bang theory account for any of the dust?

 

[Vagn]

Does the big bang theory account for any of the dust?

The Big Bang formed hydrogen, helium and a tiny amount of Lithium. The rest of the chemical elements formed by nuclear fusion processes in stars and the very heavy elements formed in supernovae.