Changes between Version 7 and Version 8 of u/erica/RadHydro


Ignore:
Timestamp:
03/29/16 19:12:09 (9 years ago)
Author:
Erica Kaminski
Comment:

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  • u/erica/RadHydro

    v7 v8  
    3737[[latex($\frac{\partial E}{\partial t}=0$)]]
    3838
    39 There is no change in the radiative energy over time. Now, other dynamics in the simulation, e.g. gravity, could change the temperature distribution in the grid and thus B(T). Only after this would happen, would we begin to see changes in E. Thus, while [[latex($4 \pi B = cE$)]], the system is in radiative equilibrium.
     39There is no change in the radiative energy over time. Now, other dynamics in the simulation, e.g. gravity, could change the temperature distribution in the grid and thus B(T). Only after this would happen, would we begin to see changes in E. Thus, while [[latex($4 \pi B = cE$)]], the system is in radiative equilibrium (right?).
    4040
     41''' Jeans unstable gas '''
    4142
     43Imagine starting with a uniform, Jeans unstable gas mass. Initially it is in radiative equilibrium, but on a freefall timescale, the gas will begin to collapse -- becoming denser and hotter as it does (recall equation for internal energy has a gravitational energy term). This will lead to regions in the grid where 4piB>cE. This will will increase the radiative energy field, and thus act to 'cool' the gas (as Erad increases, e decreases). Is this right? Thinking of radiation as a source of cooling for optically thin gas...?
     44
     45Eventually the material should become dense enough that is becomes optically thick to the radiation. Thus, despite the gas heating up through infall, it should no longer be adding these photons to the radiation field (for if it does, it will continue to cool given the equations are inverses of each other)...? We can imagine the
     46
     47the material shouldn't be able to cool through radiation.
     48
     49''' Radiation with a source '''
     50
     51Now we add a radiating source to the grid.