In September 2015, ALMA observed the center of the galaxy NGC 1332 at angular resolution 0.044 arcseconds as part of our group’s Cycle 3 program. We observed the CO(2-1) rotational emission line with the goal of mapping the rotation speed of the molecular disk at the center of the galaxy. We received the processed data from ALMA in January. The data clearly show the expected signature of a compact central mass, in the form of a central rise in rotation speed, and we fit dynamical models to the ALMA data cube to determine the central mass. This is the first ALMA observation that has resolved the radius of influence of a supermassive black hole, and the measurement gives the mass of the black hole in NGC 1332 to 10% precision. Here are links to our published paper in the Astrophysical Journal Letters and the preprint (for those who can’t directly access the journal paper).

Collaborators on this project include Benjamin Boizelle (UCI graduate student), Jeremy Darling (Colorado), Andrew Baker (Rutgers), David Buote (UCI), Luis Ho (KIAA), and Jonelle Walsh (Texas A&M).