Learning from model grids: Tracers of the ionization fraction in the ISM

The ionization fraction in neutral interstellar clouds is a key physical parameter controlling multiple and chemical processes, varying by orders of magnitude from the UV irradiated surface cloud to its cosmic-ray dominated central regions. Traditional observational tracers fraction, which mostly rely on deuteration ratios molecules like HCO + , suffer fact that deuterated are only detected tiny given Giant Molecular Cloud (GMC). In [1], we propose machine learning -based, semi-automatic method search large dataset astrochemical model results for new several relevant different ranges conditions.