Thermalized components/virialized

  • Context: Graduate 
  • Thread starter Thread starter ChrisVer
  • Start date Start date
Click For Summary
SUMMARY

This discussion focuses on the concepts of thermalization and virialization of cold dark matter (CDM) components within galactic halos. It clarifies that thermalization refers to the process through which particles reach a state of statistical equilibrium in velocity distributions, while virialization indicates that the system adheres to the virial theorem, relating kinetic and potential energy. The transition from non-thermalized to thermalized states occurs over time, particularly after disturbances such as galaxy mergers, which can disrupt the equilibrium described by the virial theorem.

PREREQUISITES
  • Understanding of the virial theorem in astrophysics
  • Knowledge of cold dark matter (CDM) dynamics
  • Familiarity with gravitational potential and its effects on particle motion
  • Concepts of statistical mechanics as applied to astrophysical systems
NEXT STEPS
  • Research the virial theorem and its applications in astrophysics
  • Study the process of thermalization in astrophysical contexts
  • Examine the effects of galaxy mergers on dark matter distributions
  • Explore statistical mechanics principles relevant to particle systems in gravitational fields
USEFUL FOR

Astronomers, astrophysicists, and students studying galaxy formation and dynamics, particularly those interested in the behavior of dark matter in galactic halos.

ChrisVer
Science Advisor
Messages
3,372
Reaction score
465
I am trying to understand what does someone mean when he or she says that a particle component (eg for CDM) is thermalized/virialized in the galactic halo...
What happens during thermalization and what's the difference between virialized/unvirialized components?

Thanks...
 
Space news on Phys.org
The Wikipedia page on the virial theorem may help, particularly the section on "in astrophysics".
 
  • Like
Likes   Reactions: ChrisVer
I think that the wiki article is just referring to the fact that matter in galaxies subject to gravitational potential, can have some statistical dispersion in velocities (the sigma), and this is related to the gravitational potential...

However it doesn't make any distinction between thermalized/non-thermalized or virialized/unvirialied or how the transition is being happening...

In case you have some cloud of CDM in the galactic halo, is that cloud virialized or not? If it is not thermalized, how does it get thermalized?
 
The idea is that over time, a galaxy will eventually relax into a state that follows the virial theorem. But when there has been a significant recent disturbance (e.g. a merger between similar-sized galaxies), the galaxy is not well-described by the virial theorem at all.
 
  • Like
Likes   Reactions: ChrisVer

Similar threads

  • · Replies 53 ·
2
Replies
53
Views
6K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 26 ·
Replies
26
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
Replies
6
Views
685