This study utilizes extremely deep high-resolution data from the Atacama Large Millimeter / submillimeter Array (ALMA). Various molecules (e.g., water, carbon monoxide) are detected in a pair of dusty starburst galaxies called ‘HXMM01’, a mega-merger that occurred 10 billion years ago (see news story on Los Angeles Times). In both galaxies, the rotation curves reach peak velocities at 500 km/s and stay at that level up to the detection limit. Such high velocities indicate enormous amount of mass enclosed within a radius smaller than our distance to the center of the Milky Way.

The study has been published on the Astrophysical Journal: Flat Rotation Curves Found in Merging Dusty Starbursts at z=2.3 through Tilted-ring Modeling

This is a follow-up study of our Nature paper: The rapid assembly of an elliptical galaxy of 400 billion solar masses at a redshift of 2.3