astrofrog / sedfitter

Python version of the SED fitter from Robitaille et al., 2007, ApJS 169 328

Home Page:http://sedfitter.readthedocs.org

Geek Repo:Geek Repo

Github PK Tool:Github PK Tool

Difference in fitting results compared to fortran sedfitter

mattpovich opened this issue · comments

In a test fit of Kurucz model atmospheres to a large (150,000) catalog of combined UKIDSS/2MASS and GLIMPSE point sources in a chunk of the Galactic midplane, I find ~10% more badly fit sources using the python sedfitter than previously with the fortran sedfitter. Best of my knowledge* all fitting parameters are the same (extinction law is your old ex_law_gl.par file, cpd=2, minimum datapoints = 4).

*Am I correct that the format/units of old extinction law files, including lots of extraneous columns, are still appropriate for the python sedfitter?

The old extinction files should still work with the new SED fitter. There was a bug I fixed in the Python SED fitter that may have been present in the old fitter that changes the reduced chi^2 values a little. Could you try and compare the chi^2 values for the best fit before and after, and see if the agreement depends on the number of valid fluxes?