Disparity between IDL foxsi_get_output_image_cube and foxsi_get_output_2d_image

[ayshih]

It's weird that foxsi_get_output_image_cube performs a unit conversion from photons to counts (because it has awareness of energies and can determine effective areas) but foxsi_get_output_2d_image just convolves in the response of the optics so the output units are still photons (or whatever the units of the source map is).

[LinErinG]

Although I agree this is a disparity, I think it's most useful this way. We want people to be able to make images without worrying about what the energy is. That way I can just make an image that will have X counts in it, where I can easily control X; this is quite useful for assessing image quality, etc. So the right way to think of it is that it's not actually starting out in photons at all. If you do want energy information included, then the image cube routine can be used for that. Alternatively, the 2d_image routine could include an energy keyword to specify energy only if desired.