Exploring and testing the ddPayne_LAMOST_DR5 results

Exploring the low-mass main sequence

This is to explore basic stellar parameters returned by PddP_L_DR5 for low-mass, very cool MS stars:

Let's start with a basic plot: the background density is the distribution of stars from DR5 with SNR_Z>30 (geared towards red stars); and the isochrone is PARSEC (3Gyrs, solar)

That brings up the first question:

There are basically no objects in this cut of DR5 whose mass (from CMD alone) is < 0.25Msun.<0 .25="" div="" m_sun.="">

Are there no such objects that got targetted? (in which band does LAMOST target)?

Or did they not go through the pipeline?

Then let's look at the basic parameters, logg and Teff 

Obviously, and perhaps unsurprisingly, things don't look good below 0.4M_sun!

The main question here for me is:

a) @Maosheng: did you not determine logg and Teff by (Bayesian) isochrone fitting, and make this an input?

b) is this simply a reflection of the training?