Modern Cosmology: Fine Tuning Problem | Adarsh

  • Context: Graduate 
  • Thread starter Thread starter xn_axe
  • Start date Start date
  • Tags Tags
    Fine tuning Tuning
Click For Summary

Discussion Overview

The discussion revolves around the relationship between the amount of dust in the Inter-Stellar Medium (ISM) and its metallicity, particularly in the context of modern cosmology. Participants explore the origins of ISM dust, its formation processes, and the implications of metallicity on star formation.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Adarsh questions why the amount of dust in the ISM scales with its metallicity, indicating a potential lack of understanding of the topic.
  • One participant suggests that larger stars create more interstellar dust and are necessary for fusing heavier elements.
  • Another participant emphasizes the importance of primordial supernovae in contributing to the dust content of the early universe, linking it to the low metallicity of that era.
  • Adarsh seeks clarification on the ISM dust-metallicity relation and proposes a hypothesis about the balance between primordial dust and star formation based on metallicity.
  • A participant explains that supernovae disperse metals into the ISM and discusses how low metallicity gas clouds can lead to the formation of more massive stars.
  • Another participant asserts that dust formation requires metals, stating that hydrogen and helium do not form solid clumps, and thus all dust originates from stellar processes.
  • Adarsh expresses gratitude for the responses and acknowledges the naivety of his initial question.

Areas of Agreement / Disagreement

Participants present various viewpoints on the relationship between dust, metallicity, and star formation, indicating that multiple competing views remain. The discussion does not reach a consensus on the underlying principles governing these relationships.

Contextual Notes

Some participants reference specific processes and phenomena related to star formation and dust creation, but the discussion contains unresolved assumptions regarding the generalizability of these claims and the specific mechanisms involved.

xn_axe
Messages
5
Reaction score
0
Hi Guys,

I have just started Modern Cosmology and please don't mind if the question is too naive.

I wanted to know why does the amount of dust in the Inter-Stellar Medium scale roughly nearly with its metallicity? Please advise.

Sorry about the incorrect heading. I can't seem to find where to edit that.

Thanks
Adarsh
 
Last edited:
Space news on Phys.org
xn_axe said:
Hi Guys,

I have just started Modern Cosmology and please don't mind if the question is too naive.

I wanted to know why does the amount of dust in the Inter-Stellar Medium scale roughly nearly with its metallicity? Please advise.

Sorry about the incorrect heading. I can't seem to find where to edit that.

Thanks
Adarsh

Larger stars create more interstellar dust and are required to fuse the heavier elements.
 
Wait i am confused. I am talking about ISM dust-metallicity relation. Kindly explain the given answer.
 
Most of that dust probably came from primordial supernova in the very early universe. Ginormous, short lived stars are believed to have been common back in the low metallicity days of the universe, and are blamed for polluting the infant cosmos.
 
So let me see if i understand this correctly. Sorry if you find this a bit naive.
The early ISM dust was with low metallicity but then the early stars burst rapidly into supernovas and filled the dust with metals which scales nearly similar to the current ISM metallicity.
But here's my question - Is this a general phenomenon? I mean if you have Primordial Dust with lesser metals, do they result in more Massive stars and Further supernova, but if the metal content is less, the Stars are created normally hence the balance is maintained anyhow.
Let me know if i am right? And if yes, what is the underlying principle dealing with the metallicity of dust and eventual star formation?
Once again sorry for the trouble. :)
 
Supernova, in general, disperse large quantities of metals into the ISM. There are scattered knots of low metallicity gas clouds throughout the universe, but, most are heavily polluted. Low metallicity gas clouds disperse heat more efficiently than 'polluted' gas clouds when they collapse. This permits more massive stars to form before the gas cloud fragments. Once the temperature reaches the critical fusion ignition temperature, a newly formed star blows off much of the remaining mass of its 'mother' gas cloud. Low metallicity allows the protostar to gravitationally bind more of the gas cloud before reaching ignition temperature. The primordial ISM was comprised of virgin hydrogen and helium. The dust you are speaking of is principally the ashes of ancient pop III stars. See http://arxiv.org/abs/1404.5391, Dust Production Factories in the Early Universe: Formation of Carbon Grains in Red-supergiant Winds of Very Massive Population III Stars, for further discussion.
 
  • Like
Likes   Reactions: 1 person
There is no hydrogen/helium dust, they just do not form solid clumps. Dust needs metals to form. I guess we can neglect primordial lithium, so all dust needs metals from stars.
 
That solves my query. Thanks to all the experts and sincere apologies for asking such a naive question.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 49 ·
2
Replies
49
Views
5K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 50 ·
2
Replies
50
Views
13K
  • · Replies 4 ·
Replies
4
Views
2K