BrownDwarf / jammer

Comparison of new synthetic model grids with data
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What priors to use for the IGRINS data #16

Open gully opened 7 years ago

gully commented 7 years ago

Here are my thoughts on priors:

uniform in logg, uniform in T_eff

These are the parameters of interest, though brown dwarfs could have strong priors based on radius and distance arguments... worth looking into.

v_z and vsini set through "empirical Bayes"

Well, kinda...

flat in logOmega (for now)

IGRINS data aren't flux calibrated.

maximum deviation for Cheb calibration polynomials

This is a huge issue. On one hand, could be unlimited to basically filter out any low frequency structure. On the other hand, it could be strict (<1% peak to valley) to force a fit to the spectral shape. Finally, it could be somewhere in between. I recommend the inbetween, with high limit: peak-to-valley to 10%.

+/-5% in sigmaAmp

We assume we have estimated the mean sigma correctly to within 5%, which is probably accurate. The real problem is the bad pixels. These should just be thrown out!!

logAmp?

We need to get this right and it's a bit involved and bespoke for each order.

GP length scale?

We need to get this right and it should be close to the same for each order.