For the first time, we used the CO Tully-Fisher relation and a Bayesian statistical method to show the dramatic evolution in gas content of star-forming galaxies, confirming previous result that galaxies were much more gaseous billions of years ago. This new method avoids correcting the inclination angles of the galaxies by assuming random disk orientations. I wrote a Python Jupyter notebook to explain the method: it’s publicly available on GitHub.

The study has been published on the Astrophysical Journal Letters: The Gas Fraction Evolution of Star-Forming Galaxies Traced by The CO Tully Fisher Relation (2018ApJ…869L..37I)