Dump MWEBV values even if they are not used by a model

[hombit]

Currently we can specify if we'd like to use the 2d Milky Way extinction map for a model and the E(B-V) value used to correct photometry for extinction is dumped to an output file as MWEBV. This means that if a model config specifies to not use Milky Way extinction, then zero MWEBV value will be written. It affects Elasticc models (d-sct, Cepheid, M-dwarf flare, dwarf novae) which turn off SNANA extinction correction and provides light curves corrected by extinction using 3-d dust maps.

I propose to always output 2-d MWEBV values and explicitly say in the documentation that it is just a function of the spherical coordinates.

[RickKessler]

Can you provide MWEBV in the library parameter list so that the simulation can automatically know to write nominal MWEBV without actually applying it. The sim is often used to explicitly turn off MWEBV, so the sim needs a clear flag to implement this new feature.

[hombit]

What do you mean by MWEBV here? The actual value used or SFD value? The first case doesn't solve Elasticc challenge problem: this value (as well as e.g. true redshift) is not known for real objects.

[RickKessler]

In the LCLIB file, please add actual MWEBV used. It serves two purposes: 1) provides true MWEBV for later analysis, and 2) it's a flag for simulation to write SFD98 MWEBV into header but NOT apply it.

[hombit]

We will do it. Maybe it should be some other name, for example EBV or extinction? I think users can be confused by the fact that LCLIB specifies one MWEBV, while output contains another one

[RickKessler]

and note that MWEBV from LCLIB is automatically renamed to avoid confusion.

[hombit]

This is a very good documentation change, thank you