Torsten is still working on the temperature spike. He has been investigating variations on the basic model:
to see how that changes the temperature spike. The spike seems to be reasonably robust to changes in the parameters.
Since the models take a long time to run, we are interested in cutting down the domain that we have to calculate. To that end, we are trying to use the transmitted continuum just past the ionization front in a static model as the input continuum for the dynamic models.
We have had problems with matching up the temperature of the two models at the boundary. Initially this was due to the Lyman lines being optically thin close to the illuminated face of the continuation model. We have solved that by using
case B no photoionization
However, there is still a difference between the T of the 2
models. Torsten is now trying to rerun the constant-pressure model to
make sure it is consistent with our continuation models, but he has
had problems with drad
becoming too small. Setting drmin 13
caused
the model to crash, so he is now trying again with drmin 12
.
drad
at the same position.
Gary is supposed to be working on this.
We have finally got this to more-or-less work. We had a lot of
problems with the fact that there is an undocumented factor of 4π
difference between the
values that are
written by punch transmitted continuum
and those that need to be
specified when giving the incident spectrum intensity in the init
file.
So, now we can run models of just the PDR part with about 300 cells that run in about 1.5 mins per iteration. Strangely, the first one of these to run does not show the temperature spike, but rather a gentle bump. However, the starting temperature is still slightly different (higher) from that of the full model, so Torsten is now experimenting with small variations in the incident flux to see if he can get one that starts at the same temperature as the models that showed the spike.