explore PSF optimization for sub-threshold galaxies

[rmandelb]

For sub-threshold galaxies, the code does some optimizations of the SED and profile, but still interpolates to get the right PSF. Is this a significant cost and can we optimize this aspect of drawing the sub-threshold galaxies as well?

[rmandelb]

@FedericoBerlfein will try this (it may be simple to implement). If it turns out to be more complicated, then this is for longer term exploration, and is not needed for the big production run.

[FedericoBerlfein]

Looked into this today, it is straightforward to modify. The code actually already does this for very faint objects (flux < 10) in stamp.py (see line 87). What I would need to know is what we consider "sub-threshold" exactly. If there is a particular AB magnitude at which we want to apply this cut, I can translate that to the flux the code uses (which is the true galaxy flux times the collecting area and exposure time). @rmandelb and @aguinot is there a particular magnitude you had in mind for a cut like this one?

[aguinot]

I think flux < 10 is a good place to start. We can check to which magnitude it correspond to but once it is implemented it will be easy to just change the flux threshold.