Wednesday, August 8, 2007

Optical depths and the atomic excitation levels densities...

After a while I have discovered what was causing that cyclopean optical depth values in my calculations. The problem was the density of the excited atomic state, it was far higher than it should be, and it is still that high. After discovering the source of the problem I have formulated various possibilities for what was the cause of this erroneous value. The possibilities were: an integration error during the calculations of the solid angle covering the star, or the accretion disk or the disk of my system, but after taking a look at these values, I have concluded that those values were fairly good; another possibility were something wrong during the velocity gradient calculations, but again these values had the correct order of magnitude that I should expect. I have not changed anything in the routine used to calculate the densities of each of the atomic excitation levels needed, so it should be correct, after all the program still works as it should work for what was his prior objectives.

After finishing checking those possibilities, I began to wonder where was this error. All the input the input values are what they should be, but the output value is nowhere near what is acceptable. Then I thought about the many iterations needed for this calculation, and I remember that all these values, for every iteration are saved in a general output data, not only the last iteration values. After that I decided to take a look about how these values evolve through each iteration, and I saw it... The problem is in the first value for density that was calculated, even before any kind of solid angle integration or even after using the routine that calculates the excitation equilibrium states for the system. I was looking for the problem in the wrong place, now I have to start looking in the right place.

And so, here I go again... I expect that this time I can find the problem.

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