[cloudy_simulations]

Re: He I 2SP3 population problem

behind I-front

The proximate cause of the plummeting 2^3S population is photoionization by Ly alpha. You can see this by including the command "no OTS lya" in your input.

Now the question is why this behavior does not happen in earlier releases of the code. Gary and I brainstormed a bit and came up with a few things that changed between C07 and C08. Here are a few suggestions for things to investigate:

1). Do C07 and C08 get the same answer for the intensity of Fe 2 1216A?

The line overlap treatment changed in C08.

It is possible that the old treatment suppressed Lya in the same sense that "no OTS lya" does.

2.) "No fine opacities" may also shed some light on the line overlap question since the fine opacity scale is the means by which the (hopefully) improved line overlap is handled.

3). Were the results converged in all the comparisons you have made?

There was also a change in the first iteration Lya treatment.

I suspect that this is not contributing because the current development version experiences the plummeting 2^3S in the second and third iterations

as well as in the first.