Compare performance of GSP-Phot to Andy's SICK code when fitting only BP/RP.

Investigate fitting BP/RP alone, RVS alone, and BP/RP+RVS simultaneously with Andy's SICK code.

Is this a route to beat APSIS?

Where can BP/RP help to estimate abundances from RVS?

Where can RVS help to improve on BP/RP?

This project employs synthetic MARCS spectra.

GSP-Phot and SICK overall agree very nicely. No algorithm clearly outperforms the other.

logg: GSP-Phot is slightly better than SICK. SICK may suffer from some convergence problems (red dots below dwarfs).

[Fe/H]: SICK is slightly better than GSP-Phot. GSP-Phot appears to systematically underestimate [Fe/H] by ~1dex for some stars. (Are these stars giants? Are they faint?)

2000 synthetic MARCS spectra in Gaia BP/RP.

Mostly Main-Sequence dwarfs but also some giants.

Teff from 4000K to 8000K.

Test spectra created by GOG. (Not by our own forward models!)