A Bayesian direct method implementation to fit emission line spectra: Application to the primordial He abundance determination

Understand

This work presents a Bayesian algorithm to fit the recombination and collisionally excited line spectra of gas photoionized by clusters of young stars.

• The current model consists in fourteen dimensions: two electron temperatures, one electron density, the extinction coefficient, the optical depth on the $HeI$ recombination lines and nine ionic species.
• The results are in very good agreement with those previously published using the traditional methodology.
• The probabilistic programming library PyMC3 was chosen to explore the parameter space via a NUTs sampler.