Interstellar Medium: Est. Mean Mass of Particle

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SUMMARY

The estimated mean mass of a particle in the interstellar medium (ISM) is approximately 2 atomic mass units, primarily due to the dominance of molecular hydrogen (H2) in the ISM. This estimate accounts for the presence of neutral atomic hydrogen (H), which has a mass of 1 atomic mass unit, but is balanced by heavier molecular species and dust. The discussion emphasizes the importance of considering mass on an average basis, particularly in the galactic plane.

PREREQUISITES
  • Understanding of interstellar medium (ISM) composition
  • Basic knowledge of atomic mass units
  • Familiarity with molecular hydrogen and its properties
  • Concept of mass averaging in astrophysics
NEXT STEPS
  • Research the composition and characteristics of the interstellar medium
  • Study the properties of molecular hydrogen (H2) in astrophysics
  • Learn about the role of dust and ionized gas in the ISM
  • Explore methods for measuring average atomic mass in astrophysical contexts
USEFUL FOR

Astronomers, astrophysicists, and students studying cosmic structures and the properties of the interstellar medium will benefit from this discussion.

popffabrik1
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Hey, can anybody tell me what the estimate is on the mean mass of a particle in the interstellar medium? I would guess around 1-10 proton masses?
 
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Just for fun, I will guess too.
I think you probably mean the ISM in the plane of our galaxy

I think you mean to average on a MASS basis.

So if most of the mass is in the form of neutral gas, then for a first approximation of the average, I can neglect dust and ionized stuff.

Eventually someone who has a definite figure will reply. I would guess the average atomic weight is 2.
(because I think the ISM is dominated by molecular hydrogen.
there would also be some neutral atomic hydrogen with weight 1 but that would tend to be balanced out by the heavier molecular species and the dust)

BTW welcome to physicsforums, Mr. Popffabrik.
I like the name, it seems it could be a nickname for the LHC collider. "bang factory"
 
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