The CO-to-H<sub>2</sub> Conversion Factor
The CO-to-H<sub>2</sub> Conversion Factor
CO line emission represents the most accessible and widely used tracer of the molecular interstellar medium. This renders the translation of observed CO intensity into total H2 gas mass critical to understand star formation and the interstellar medium in our Galaxy and beyond. We review the theoretical underpinning, techniques, and …