Thermal energy density of the milky way

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SUMMARY

The average thermal energy density of the Milky Way disk can be computed using the equation E = (3/2) kT, where k is the Boltzmann constant and T is the temperature in Kelvin. Given the interstellar medium's atomic hydrogen at 100 K and a number density of 2E-7 m-3, the thermal energy density is derived by multiplying the calculated energy E by the number density. For magnetic energy density, the correct formula is B2/8π, applicable in the SI system, where B is the magnetic field strength of 3E-10 T.

PREREQUISITES
  • Understanding of thermal physics concepts, specifically the equation E = (3/2) kT.
  • Familiarity with the properties of atomic hydrogen and its behavior at low temperatures.
  • Knowledge of magnetic field strength and its implications in energy density calculations.
  • Proficiency in using SI units for physical equations, particularly in the context of magnetic energy density.
NEXT STEPS
  • Research the Boltzmann constant and its application in thermal energy calculations.
  • Study the derivation and application of the formula for magnetic energy density, B2/8π.
  • Explore the properties of the interstellar medium and its impact on astrophysical calculations.
  • Learn about the significance of number density in calculating energy densities in various physical contexts.
USEFUL FOR

Astronomy students, astrophysicists, and anyone interested in understanding thermal and magnetic energy densities in astrophysical contexts.

acdurbin953
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Homework Statement


Interstellar medium is composed of atomic hydrogen at 100 K and number density 2E-7 m-3. Compute the average thermal energy density of the milky way disk. Then find the average magnetic energy density given the magnetic field strength of 3E-10 T.

Homework Equations


E=3/2 kT, maybe? Trying to recall some stuff from thermal physics.

The Attempt at a Solution


Embarrassingly, I had no idea where to begin with this problem, and have no idea if I'm on the right track.
So far I have solved for E, and was going to multiply my value by the number density to find the thermal energy density. There's nothing in our book or notes about how to solve a problem like this (no idea why), so I feel totally lost.
I have no idea how to solve fore the magnetic energy density. Any hints about where to start would be very, very helpful.
 
Physics news on Phys.org
Your method of finding the thermal energy density looks good.

Did you try a web search for magnetic field energy density?
 
I did, and found magnetic field energy density is B2/8π? Never seen that one before, but is that correct for this situation?
 

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