Help with the Virial Theorem please

  • Context: Undergrad 
  • Thread starter Thread starter Alfie114
  • Start date Start date
  • Tags Tags
    Theorem Virial theorem
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
4 replies · 3K views
Alfie114
Messages
3
Reaction score
0
TL;DR
I have a question about the virial theorem as applied to a cluster of stars.
Anyone able to help if I provide you with more details?
 
Astronomy news on Phys.org
OK we have a star cluster (the system) which is made up from stars (total mass M sub *) and gas (total mass M sub g). The stars and gas are all distributed as spheres of constant density and a finite radius r sub c.

The total mass of the stars and the gas is different but we can assume that M sub g = f*M sub *

If the system is unrotating and in equilibrium how do we calculate the kinetic energy in terms of r sub c, f and M sub *?

We can take 2KE + PE = 0 where KE = (-3/5) (GM^2/R) and PE = (3kT/2)*n where n is the total number of particles = (M/mu*m sub H) where mu=1 and m sub H is the mass of a hydrogen atom.
 
Alfie114 said:
OK we have a star cluster (the system) which is made up from stars (total mass M sub *) and gas (total mass M sub g). The stars and gas are all distributed as spheres of constant density and a finite radius r sub c.

The total mass of the stars and the gas is different but we can assume that M sub g = f*M sub *

If the system is unrotating and in equilibrium how do we calculate the kinetic energy in terms of r sub c, f and M sub *?

We can take 2KE + PE = 0 where KE = (-3/5) (GM^2/R) and PE = (3kT/2)*n where n is the total number of particles = (M/mu*m sub H) where mu=1 and m sub H is the mass of a hydrogen atom.
You need to use math latex notation. Its hard to understand your equations like this.
 
Ok I've got these where omega is the potential energy
1575636887584.png
1575636809181.png