Update ThAr linelist based on LFC cross-comparisons

[shalverson]

Derive new Thorium linelist based on actual KPF spectra, filtered from the Redman atlas. Particularly critical for the bluest orders on the green chip. Use data from 4/30, where we had both LFC and ThAr across all orders in the green chip.

[shalverson]

@aaronhouseholder @bjfultn

Here's a linelist from a 'good' thorium solution that I derived, comparing to NEID. The fit yield (number of lines per order relative to the number of available atlas lines in that order) is >70% for most orders. In other words, there's not much left to be fit.

Thorium_linelist_sph_12_5_23.txt

This linelist was used to generate this coverage map

[shalverson]

I don't have an easy way to format this into whatever npy formatting is used for the current pipeline, but I strongly suggest we make some code to make the WLS algorithms compatible with a basic txt file list of wavelengths.

[awhoward]

For expediency, I suggest that @aaronhouseholder convert @shalverson's .txt file into the .npy format. I'll create a separate Github issue some build functionality for reading ASCII line lists.

[awhoward]

During the DRP hack session today, we talked about writing methods to score each line according to several criteria. (@shalverson mentioned this before as well.). This code could be part of the DRP, though used infrequently and might be in notebook form. It could utilize the WLSDict objects to loop over lines.

Possible criteria:

1. Absence of nearby lines
2. Amplitude
3. Line symmetry
4. Line width
5. Slope and offset of background light